Introduction: Reupholster a Chair From the Bones Up
My sister inherited this lovely framed chair from our mother. It has been reupholstered at least once before; I remember my mother and grandmother working on it for about a week when I was 8 or 9. It made a huge mess and took up the whole living room. Even at that age I disliked their fabric choice so I was very happy to redo it after so long. It was quite a bit of work and I made a couple mistakes I had to fix (you won't, though, because I'll tell you how to avoid them) but it should give joy and comfortable sittings for many years.
Step 1: Tools & Materials
The tools required are not too bad of a list, although some are fairly specialized.
- tape measure
- hammer
- nail remover if the hammer doesn't have one
- nail set
- heavy duty staple remover or large flat-head screwdriver
- heavy duty scissors
- webbing stretcher
- heavy sharp curved upholstery needle
- pneumatic stapler (electric is manageable although they suck, hand stapler possible with difficulty)
- bolt cutter, or dremel/drill with small cutting wheel (if you got the wrong size zigzag springs)
- about 4 yards of outer fabric
- about 3 yards of inner fabric
- a bit over a yard of fabric to cover the chair bottom
- 2" foam, medium density, for the chair seat
- 1" foam, medium density, for the chair back
- several yards of Dacron batting (often comes in 3 yd packages which is enough for this kind of chair)
- seat edge roll, enough for at least the seat bottom but nice to have on the back edges as well (see step 4)
- jute webbing
- couple yards of burlap
- LOTS of staples
- 9 pc 10" coil springs for the seat
- 4 pc 20" zigzag springs for the back (I got 24" by accident and had to cut them down. pick a length that is a little longer than the length of the seat back, so you get a nice curve instead of a flat back)
- spring clips for the zigzag springs
- "blue tacks" and "no-sag" nails, supposedly for the twine and zigzag springs respectively but I used them both for both as they were very different sizes and there had been a lot of nailing into this frame already
- spring twine
- thin cardboard
- polyester upholstery thread
- decorative upholstery nails
Step 2: Removing Old Upholstery
This chair was in quite bad shape. The bottom had come loose and been torn at by cats; it had been in storage for a while with boxes on the seat and the springs were all falling down; the horsehair had gotten moldy or something and was also coming to bits. I took the old upholstery off gradually to learn about how the inside had been done. I did end up doing it somewhat differently; primarily I did not use any horsehair stuffing, but used foam and polyester batting instead. My hope is that these will not break down as unpleaseantly.
I saved all the pieces of outer fabric in case I needed a pattern for the new fabric, but this chair was all rectangles and I didn't use it. I saved the decorative nails as well (those that hadn't fallen out were in perfect shape) but again didn't use them as we'd chosen new ones. The horsehair, cotton wadding, cotton lining fabric, burlap, and jute webbing I threw out immediately. And then I had to vaccuum. This part took about 4 hours as I took a bunch of pictures and studied the construction. The very last step was to pull out all the nails and staples and inspect the frame for damage. I was lucky in that the frame was fine except for one missing leg support at the rear, which had been missing for years anyway and we decided not to bother replacing.
I saved all the pieces of outer fabric in case I needed a pattern for the new fabric, but this chair was all rectangles and I didn't use it. I saved the decorative nails as well (those that hadn't fallen out were in perfect shape) but again didn't use them as we'd chosen new ones. The horsehair, cotton wadding, cotton lining fabric, burlap, and jute webbing I threw out immediately. And then I had to vaccuum. This part took about 4 hours as I took a bunch of pictures and studied the construction. The very last step was to pull out all the nails and staples and inspect the frame for damage. I was lucky in that the frame was fine except for one missing leg support at the rear, which had been missing for years anyway and we decided not to bother replacing.
Step 3: Seat Springs
Place your chair frame upside down and supported in a way you can get at it easily. Decide how many strips of jute webbing you can get across, and how many front-to-back, without them squishing each other. I managed 5 in each direction. You can mark the chair frame if you like. Staple down all the strips in one direction first, then the other, interweaving as you go.
Do each strip like this. Lay the webbing loosely across where you're going to staple it. Put 3 or 4 staples near the end of the webbing, leaving about a 2" or 3" tail. Make sure to staple near the center of the wooden bar so the staples are less likely to pull through the side of the wood. Fold the tail back over tightly and staple again, in between where you stapled before. For the other end, use your webbing stretcher which unfortunately I didn't take any pictures of as it needed two hands (but see this video at about one minute in. Use of a gooseneck stretcher is similar but instead of a loop of webbing and a dowel to secure it to the stretcher, there are spikes that go through the webbing). A second person is useful here while you get the hang of it, but it's doable by one with a bit of practice. Make sure to get all the webbing strips nice and tight!
Once your webbing is on, lay out the springs. You probably will have 4 or 9, unless your chair is a very strange shape. Sew each spring to the webbing in at least three places with upholstery thread, nice and tight. There are also spring clips available for this purpose but I did not use those.
Now you are ready to tie the springs together, and to the frame. The purpose of tying is to compress them so they are not so bouncy, but merely softly giving when sat upon, and to prevent them from moving separately and making gaps in the seat. When they're all tied, you should be able to push on one and see all the rest move a little too.
Hammer in a pair of nails halfway, to the frame nearest to the center of each spring. Cut a loooooong piece of twine, maybe four times as long as the chair frame plus a bunch extra. Fold it in half and make a lark's head knot around the pair of nails, with the loose ends coming out from under the crossing twine towards the center of the chair. Hammer the nails down all the way while keeping tension on the twine, so the twine is secured to the frame tightly.
Hold the closest spring down to where you want it to sit when the chair is done -- this should be a little lower than the desired seat level, as you'll be putting another 2" of foam and padding on as well. Using a double half hitch (or two overhand knots), tie one strand to the highest curl of the spring at its squished level. Bring the strand across to the other side of the spring and tie another knot. Compress the next spring and tie it the same way. Continue until you run out of springs, and then fasten the twine to the frame with another nail with the twine knotted around the nail shaft. Check out the notes in the pictures for this, there are some useful tips there.
Using the same technique, tie the following sections:
Do each strip like this. Lay the webbing loosely across where you're going to staple it. Put 3 or 4 staples near the end of the webbing, leaving about a 2" or 3" tail. Make sure to staple near the center of the wooden bar so the staples are less likely to pull through the side of the wood. Fold the tail back over tightly and staple again, in between where you stapled before. For the other end, use your webbing stretcher which unfortunately I didn't take any pictures of as it needed two hands (but see this video at about one minute in. Use of a gooseneck stretcher is similar but instead of a loop of webbing and a dowel to secure it to the stretcher, there are spikes that go through the webbing). A second person is useful here while you get the hang of it, but it's doable by one with a bit of practice. Make sure to get all the webbing strips nice and tight!
Once your webbing is on, lay out the springs. You probably will have 4 or 9, unless your chair is a very strange shape. Sew each spring to the webbing in at least three places with upholstery thread, nice and tight. There are also spring clips available for this purpose but I did not use those.
Now you are ready to tie the springs together, and to the frame. The purpose of tying is to compress them so they are not so bouncy, but merely softly giving when sat upon, and to prevent them from moving separately and making gaps in the seat. When they're all tied, you should be able to push on one and see all the rest move a little too.
Hammer in a pair of nails halfway, to the frame nearest to the center of each spring. Cut a loooooong piece of twine, maybe four times as long as the chair frame plus a bunch extra. Fold it in half and make a lark's head knot around the pair of nails, with the loose ends coming out from under the crossing twine towards the center of the chair. Hammer the nails down all the way while keeping tension on the twine, so the twine is secured to the frame tightly.
Hold the closest spring down to where you want it to sit when the chair is done -- this should be a little lower than the desired seat level, as you'll be putting another 2" of foam and padding on as well. Using a double half hitch (or two overhand knots), tie one strand to the highest curl of the spring at its squished level. Bring the strand across to the other side of the spring and tie another knot. Compress the next spring and tie it the same way. Continue until you run out of springs, and then fasten the twine to the frame with another nail with the twine knotted around the nail shaft. Check out the notes in the pictures for this, there are some useful tips there.
Using the same technique, tie the following sections:
- all 2 or 3 front-to-back rows of springs
- all 2 or 3 side-to-side rows of springs
- two diagonal corner-to-corner rows of springs
Step 4: Seat Cushioning
With the springs in, you're ready for the upper layer of seat padding. Protect this layer by first covering the metal springs with a layer of heavy burlap. Cut burlap more or less to size and stuff the back edge between the top of the frame bar that the seat spring webbing is attached to, and the lower bar of the chair back. Staple it down across the back of the chair, pulling it fairly tight side-to-side. Then from the front, staple the rest down to the top of the seat frame, firmly but not tight enough to change the spring shape (this shape should remain how you tied it). Trim excess from the edges.
Next add some edge roll to the front and side edges of the seat. This is a kind of thick, heavy piping that protects the sitter, if they happen to push the seat far enough down, from the edge of the wooden frame. Staple it over the burlap so that the edge of the roll is right at the edge or ever so slightly farther out, but not inside the edge or the edge will be perceptible. Cut it off very close to the arm supports if you have any. It is also nice to put edge roll on the seat back; I didn't do this because I only had enough for the seat.
Cut a piece of 2" thick foam to about 1" bigger than the seat size and lay it on top. With the foam carefully centered, mark the arm verticals, and then trim away a bit in between the marks. Don't trim the full depth of the arm verticals, but let the foam puff up a little in the middle so it presses against the arms when you're done trimming, instead of leaving gaps.
Cut a piece of dacron batting long enough to cover the seat with a few inches extra at front & back (and sides if your dacron is wide enough or your seat is thin enough). Lay the dacron over the foam and stuff the back end through where you stuffed the burlap (you'll be doing a lot more stuffing through there so get used to it). Staple in place - doesn't have to be super taut as the next layers will do the shaping, this is just to prevent the dacron from shifting underneath. Staple around the front and sides as well, bringing the dacron down well over the edge roll to the bottom of the frame, where you can. At the arm verticals, stuff the dacron down under the foam; cut a small slit if you need to but you probably won't need to as the dacron will stretch easily.
Next add some edge roll to the front and side edges of the seat. This is a kind of thick, heavy piping that protects the sitter, if they happen to push the seat far enough down, from the edge of the wooden frame. Staple it over the burlap so that the edge of the roll is right at the edge or ever so slightly farther out, but not inside the edge or the edge will be perceptible. Cut it off very close to the arm supports if you have any. It is also nice to put edge roll on the seat back; I didn't do this because I only had enough for the seat.
Cut a piece of 2" thick foam to about 1" bigger than the seat size and lay it on top. With the foam carefully centered, mark the arm verticals, and then trim away a bit in between the marks. Don't trim the full depth of the arm verticals, but let the foam puff up a little in the middle so it presses against the arms when you're done trimming, instead of leaving gaps.
Cut a piece of dacron batting long enough to cover the seat with a few inches extra at front & back (and sides if your dacron is wide enough or your seat is thin enough). Lay the dacron over the foam and stuff the back end through where you stuffed the burlap (you'll be doing a lot more stuffing through there so get used to it). Staple in place - doesn't have to be super taut as the next layers will do the shaping, this is just to prevent the dacron from shifting underneath. Staple around the front and sides as well, bringing the dacron down well over the edge roll to the bottom of the frame, where you can. At the arm verticals, stuff the dacron down under the foam; cut a small slit if you need to but you probably won't need to as the dacron will stretch easily.
Step 5: Seat Fabric
For the final seat piece, you'll cover the dacron with canvas, and then with the upholstery fabric. The canvas gives shape and strength, and the upholstery fabric (besides being pretty) smooths it all out.
Cut a piece of canvas about 15" longer than the seat. Measure the width of the back part that you're gonna stuff it through. Fold in half lengthwise, measure half your width from the fold, and cut out the corners so just the middle section has to get stuffed through (see pictures for this). Stuff the back edge through and pull enough out that the corner cuts butt up against the seat back frame. Put some staples in the middle, but hold off on the sides as you'll most likely need to tug them farther later on.
From the seat front, pull the canvas taut in the middle and staple a few in the center front as well. Now you have a front-back stable line and can work on the arms. Tug the fabric to one side, enough so it's smooth but not enough to pull the centerline off, and stuff it down between the arm and the seat padding. The excess will fold up. On this excess, mark the edges of the arm verticals, and the top of the frame. Pull the fabric back up and cut a Y shape in the rectangle made by the arm vertical marks and the frame top. You can now stuff it all back, but the part that folded up before can now be stretched down on either side of the arm vertical, and stapled to the seat frame.
Once the center bits on all 4 sides are tacked in place, staple towards the edges, pulling the canvas tight as you go. You will likely find that you have to restaple some bits, and there may be some small gaps or folds. As long as these are just cosmetic and not structural, you can ignore them, as the fashion outer fabric will cover a multitude of sins. I was really surprised how well it covered up some of my errors.
Once the canvas is on, do the exact same process for the outer fabric. There are a couple minor differences:
Cut a piece of canvas about 15" longer than the seat. Measure the width of the back part that you're gonna stuff it through. Fold in half lengthwise, measure half your width from the fold, and cut out the corners so just the middle section has to get stuffed through (see pictures for this). Stuff the back edge through and pull enough out that the corner cuts butt up against the seat back frame. Put some staples in the middle, but hold off on the sides as you'll most likely need to tug them farther later on.
From the seat front, pull the canvas taut in the middle and staple a few in the center front as well. Now you have a front-back stable line and can work on the arms. Tug the fabric to one side, enough so it's smooth but not enough to pull the centerline off, and stuff it down between the arm and the seat padding. The excess will fold up. On this excess, mark the edges of the arm verticals, and the top of the frame. Pull the fabric back up and cut a Y shape in the rectangle made by the arm vertical marks and the frame top. You can now stuff it all back, but the part that folded up before can now be stretched down on either side of the arm vertical, and stapled to the seat frame.
Once the center bits on all 4 sides are tacked in place, staple towards the edges, pulling the canvas tight as you go. You will likely find that you have to restaple some bits, and there may be some small gaps or folds. As long as these are just cosmetic and not structural, you can ignore them, as the fashion outer fabric will cover a multitude of sins. I was really surprised how well it covered up some of my errors.
Once the canvas is on, do the exact same process for the outer fabric. There are a couple minor differences:
- on the front and sides of the seat, you will tuck the fabric under the frame and staple to the bottom of it, instead of to the sides
- at the side back, you will fold the rear edge of the fabric under itself vertically, to make a clean line at the edge of the rear leg (on the canvas this is just a cut edge). You might have to clip an inside corner to get it to fold nicely
- on the front edge, you will wrap the side fabric to the front and fold the front piece at a slight angle, so you can staple to the frame bottom but still avoid the front chair leg.
Step 6: Back Springs
While it is possible to sew and tie coil springs vertically for a chair back, the zig-zag or sinuous springs are MUCH easier and faster! (They will work on seats as well and much modern furniture uses them. They don't feel quite as luxurious on the ass, though, so high end chairs & sofas still use coil springs for the seats.) Zig-zag springs install via a small clip that you simply nail onto the frame. Decide how many springs you want - they should be about 3-4 inches apart, center to center - and mark the spacing on the frame. You may want to nail the lower spring clips on before doing the seat upholstery, as it is annoying to hammer with the seat cushion in the way, but you may not, as the clip corners are sharp and might tear the seat fabric as you are installing it, not to mention your knuckles. I put them on after the seat, as you can see in the pics (although not because I'd thought that through).
Nail each clip on using one nail, through the center hole. The zig-zag springs come coiled, and have springiness in the coil direction as well as the zig-zag direction, so the clips should be placed to pull the springs apart rather than push them together as it would be if they were normally straight. Once the clips are nailed down, set a spring in the lower clip and pull it up to the upper clip. Then put in two more nails to each clip, bending the clip down over the spring and holding it firmly in place.
And the zig-zag springs need tying too! I had done the arms before remembering this so the pictures are slightly out of order. In the same way as the seat spring twine was attached, nail and tie twine to the sides at three evenly spaced distances (four if your seat is very tall, two if it is very short). For these springs you do not need to squish them before tying, but do make sure the twine is tight between all the knots or it won't be very effective in keeping the springs moving as a unit. Keep the twine horizontal, tie from the middle of one zig-zag curve to the middle of the next one over. A simple overhand knot is sufficient. Tie the twine off in the same manner, tied around a nail you then hammer completely in.
Nail each clip on using one nail, through the center hole. The zig-zag springs come coiled, and have springiness in the coil direction as well as the zig-zag direction, so the clips should be placed to pull the springs apart rather than push them together as it would be if they were normally straight. Once the clips are nailed down, set a spring in the lower clip and pull it up to the upper clip. Then put in two more nails to each clip, bending the clip down over the spring and holding it firmly in place.
And the zig-zag springs need tying too! I had done the arms before remembering this so the pictures are slightly out of order. In the same way as the seat spring twine was attached, nail and tie twine to the sides at three evenly spaced distances (four if your seat is very tall, two if it is very short). For these springs you do not need to squish them before tying, but do make sure the twine is tight between all the knots or it won't be very effective in keeping the springs moving as a unit. Keep the twine horizontal, tie from the middle of one zig-zag curve to the middle of the next one over. A simple overhand knot is sufficient. Tie the twine off in the same manner, tied around a nail you then hammer completely in.
Step 7: Arms
The arms could be done at any point before now but they need to be done before the back gets any further than the springs. The layers are foam, dacron, fabric. I used 1" foam but 1-1/2 would probably have been better, or another couple layers of dacron, or something. They turned out a little harder than I'd have liked, although not uncomfortable.
Cut foam the same length as and about an inch, inch and a half wider than the armrest. Cut dacron wide enough to go around the whole armrest, and a few inches longer than the foam. Cut fabric a little longer than the dacron. Hold all these layers together and wrap the front edge of the fabric around and under the other two layers, lining up the fold with the line on the armrest that indicates the end of the padding. Roll the inside edges under the armrest and put in a couple of staples to hold it. Then from the outside, pull the fabric to a good tightness, being careful not to shift the foam or dacron to either side, and staple under the arm. Trim the under-arm edge close to the staples.
At the back end of the arm, cut a few slits in the fabric at the top and inside, pointing towards the armrest corners, to allow the fabric to relax against the frame. Make sure not to cut the outer edge of the fabric as this will cover the section of the outside frame edge where the seat back fabric is blocked by the arm and cannot reach.
Cut foam the same length as and about an inch, inch and a half wider than the armrest. Cut dacron wide enough to go around the whole armrest, and a few inches longer than the foam. Cut fabric a little longer than the dacron. Hold all these layers together and wrap the front edge of the fabric around and under the other two layers, lining up the fold with the line on the armrest that indicates the end of the padding. Roll the inside edges under the armrest and put in a couple of staples to hold it. Then from the outside, pull the fabric to a good tightness, being careful not to shift the foam or dacron to either side, and staple under the arm. Trim the under-arm edge close to the staples.
At the back end of the arm, cut a few slits in the fabric at the top and inside, pointing towards the armrest corners, to allow the fabric to relax against the frame. Make sure not to cut the outer edge of the fabric as this will cover the section of the outside frame edge where the seat back fabric is blocked by the arm and cannot reach.
Step 8: Back Padding
As with the seat, the first layer over the springs is burlap. Cut a piece big enough to cover the seat back and wrap around the frame; cut out the corners as needed, stuff it through the gap between the seat and back, and staple it to the inside of the frame. Cut slits to avoid the armrests, and trim edges as needed. At the top corners you'll get some overlap, just trim as well as you can and staple down. The burlap again does not need to compress the springs, just needs to get out of its own way and that of the upcoming layers.
Next is the 1" foam, which also is done very similarly to the seat foam, with notches for the armrests. Make sure it's long enough to get stuffed a little into the stuffing place, and wrap well over the top of the frame. Cut the dacron as well, stuff it in, staple it down in a few spots so it doesn't slip while you go on. All of this should be quite familiar by now.
Next is the 1" foam, which also is done very similarly to the seat foam, with notches for the armrests. Make sure it's long enough to get stuffed a little into the stuffing place, and wrap well over the top of the frame. Cut the dacron as well, stuff it in, staple it down in a few spots so it doesn't slip while you go on. All of this should be quite familiar by now.
Step 9: Back Fabric
The back canvas and outer fabric are, again, very similar to the seat. Cut a piece of canvas big enough, trim the bottom corners so there is a section big enough to stuff through between the cushions, and staple the center part down. Pull the top part up and over, and staple the center down. Mark where the arms are, and cut slits so the canvas can get stuffed in between the foam and the armrest. Pull the upper and lower side pieces around and staple. Work from the center towards the corners, folding and stapling as you go, and do not worry too much about wrinkles in the canvas as the outer fabric will totally smooth it all down.
The outer fabric is basically the same with a couple exceptions. You will want to cover the lower part of the frame uprights with the same piece of fabric as the back, so instead of cutting away the corners of the fabric, cut a Y shape to work around the width of the frame pieces. See the pic for clarity.
When working around the armrests, you'll have three sections of fabric: the upper part of the back, the fabric from the armrests, and the lower part of the back. Fold each of these horizontally such that the folded edges butt up against each other and no frame wood shows through. Staple at the back and sew the butted folds together invisibly with heavy upholstery thread and a curved needle.
To do the sewing, thread the needle with 15 or 18 inches of thread, and make a knot at one end. Hide the knot deep in the fabric under the armrest for the lower section, and either deep in the fold between the armrest and back on the upper section, or in the part that's around the back if you want to sew from back to front. It is possible to use a straight needle as well, but a curved needle makes it a little easier to bring the point back up from underneath, catching 1/4" or so of fabric in each stitch. Smaller stitches are fine but try not to get too much bigger than 1/4" if you can or you risk the thread being visible. Of course, if the thread matches the fabric, it's gonna be very hard to see even if some of your stitches come over top of the fabric, so don't stress about this too much.
At the lower side, there will be a flap of fabric that should be an inch or more longer than the bottom of the chair seat, where the seat cover is folded under and stapled. The back edge of the seat should be a nice folded edge, which you can butt up another folded edge to. Using heavy upholstery thread and a curved needle, sew the two butted folds together invisibly. It is slightly easier to do this sewing before the fabric is stapled to the back of the chair leg but it doesn' t make a lot of difference. Fold the bottom up to match the lower edge of the seat, and staple around back if you didn't yet.
The outer fabric is basically the same with a couple exceptions. You will want to cover the lower part of the frame uprights with the same piece of fabric as the back, so instead of cutting away the corners of the fabric, cut a Y shape to work around the width of the frame pieces. See the pic for clarity.
When working around the armrests, you'll have three sections of fabric: the upper part of the back, the fabric from the armrests, and the lower part of the back. Fold each of these horizontally such that the folded edges butt up against each other and no frame wood shows through. Staple at the back and sew the butted folds together invisibly with heavy upholstery thread and a curved needle.
To do the sewing, thread the needle with 15 or 18 inches of thread, and make a knot at one end. Hide the knot deep in the fabric under the armrest for the lower section, and either deep in the fold between the armrest and back on the upper section, or in the part that's around the back if you want to sew from back to front. It is possible to use a straight needle as well, but a curved needle makes it a little easier to bring the point back up from underneath, catching 1/4" or so of fabric in each stitch. Smaller stitches are fine but try not to get too much bigger than 1/4" if you can or you risk the thread being visible. Of course, if the thread matches the fabric, it's gonna be very hard to see even if some of your stitches come over top of the fabric, so don't stress about this too much.
At the lower side, there will be a flap of fabric that should be an inch or more longer than the bottom of the chair seat, where the seat cover is folded under and stapled. The back edge of the seat should be a nice folded edge, which you can butt up another folded edge to. Using heavy upholstery thread and a curved needle, sew the two butted folds together invisibly. It is slightly easier to do this sewing before the fabric is stapled to the back of the chair leg but it doesn' t make a lot of difference. Fold the bottom up to match the lower edge of the seat, and staple around back if you didn't yet.
Step 10: Back of Chair
The front of the chair is now complete, and the open back just needs to be covered up nicely. It is possible to use a different fabric (like you will for the underneath), if the chair will always sit against a wall, for example, or if there is simply not enough outer fabric. Some sofa makers do this to save costs. But I prefer the lovely upholstery fabric all around. The technique is the same in either case.
The backing fabric is held in place by nails and cardboard - the cardboard produces a nice straight edge when the fabric is folded over. It isn't easy to keep it tight at the sides, though, because the strip has to be installed from the inside... this will be clearer in a bit. But the sides, I also sewed down, because it looked better.
There is a product available which is cardboard strips with nails pre-inserted; however I had a lot of nails already and it's always easy to find scrap cardboard so I just made some. The strips hold the fabric cover tight to the back by nailing in, and give a nice clean folded edge from the cardboard. Use a heavy cardstock rather than corrugated, which is too thick. Back of a pad of paper is a good thickness (and if you can't find any larger cardboard than a legal pad, just overlap two short strips by an inch and one or two nails).
First up, take your piece of fabric (big enough to cover the whole back, with a couple inches of margin on all edges) and lay it upside down over the back of the chair. For this one, you can just place the cardboard and nail it right in, easy peasy. Just make sure the edge is straight, both the cardboard edge and the fabric edge, so the fabric doesn't pull sideways further down.
For the sides, create your pre-nailed strips at about 3/4 the length of the back. Find where the nice edge fold ought to be, and tuck the strip inside the fabric with the edge along that fold, and the nails going through the folded edge, facing toward the chair frame. Do both sides, making sure they're even and not drooping in the middle, and hammer the nails in through the fabric. Be careful with this as excessive hammering may damage the fibers above the nail head.
Sew the edges together from the outside, as with the side back seat cushion edge. This does take a bit of time but will provide the nicest finish, and allow you to tuck in any stray fibers. Deal with the bottom before you quite finish the sewing - and in fact you might not have to sew the whole way down, it depends on how the cardboard came out. For the bottom, you don't need a cardboard strip, just staple it underneath as with all the rest of the bottom edges. You will likely have to make a snip at the inside leg edge to allow the fabric over the leg itself to be folded up, while the rest is folded under. See the pic for this. Once that's done, sew the bottom corners down, and that's the back done.
The backing fabric is held in place by nails and cardboard - the cardboard produces a nice straight edge when the fabric is folded over. It isn't easy to keep it tight at the sides, though, because the strip has to be installed from the inside... this will be clearer in a bit. But the sides, I also sewed down, because it looked better.
There is a product available which is cardboard strips with nails pre-inserted; however I had a lot of nails already and it's always easy to find scrap cardboard so I just made some. The strips hold the fabric cover tight to the back by nailing in, and give a nice clean folded edge from the cardboard. Use a heavy cardstock rather than corrugated, which is too thick. Back of a pad of paper is a good thickness (and if you can't find any larger cardboard than a legal pad, just overlap two short strips by an inch and one or two nails).
First up, take your piece of fabric (big enough to cover the whole back, with a couple inches of margin on all edges) and lay it upside down over the back of the chair. For this one, you can just place the cardboard and nail it right in, easy peasy. Just make sure the edge is straight, both the cardboard edge and the fabric edge, so the fabric doesn't pull sideways further down.
For the sides, create your pre-nailed strips at about 3/4 the length of the back. Find where the nice edge fold ought to be, and tuck the strip inside the fabric with the edge along that fold, and the nails going through the folded edge, facing toward the chair frame. Do both sides, making sure they're even and not drooping in the middle, and hammer the nails in through the fabric. Be careful with this as excessive hammering may damage the fibers above the nail head.
Sew the edges together from the outside, as with the side back seat cushion edge. This does take a bit of time but will provide the nicest finish, and allow you to tuck in any stray fibers. Deal with the bottom before you quite finish the sewing - and in fact you might not have to sew the whole way down, it depends on how the cardboard came out. For the bottom, you don't need a cardboard strip, just staple it underneath as with all the rest of the bottom edges. You will likely have to make a snip at the inside leg edge to allow the fabric over the leg itself to be folded up, while the rest is folded under. See the pic for this. Once that's done, sew the bottom corners down, and that's the back done.
Step 11: Finishing
There are only two more things, both of which are optional. I finished the bottom with a piece of thin black fabric just because. Cut to size; fold the edges under; staple in place. You are expert at this by now.
Also this chair was designed for decorative nails, and we had gotten some pretty new ones. Nailing these on is a simple matter of a hammer. Make sure to space them well, especially at areas like the side front corners, between the armrest vertical and the corner of the seat, as you don't want Unsightly Holes in the pattern. If, like mine, your chair had decorative nails in it before, you may find yourself nailing into existing holes. If your new nails aren't slightly longer than the old ones, use some wood glue in each hole that's loose. There is very little pressure on these nails so glue will be sufficient to keep them in place.
I forgot to take a picture showing the rest of the nails but really you can put them in however you want.
Also this chair was designed for decorative nails, and we had gotten some pretty new ones. Nailing these on is a simple matter of a hammer. Make sure to space them well, especially at areas like the side front corners, between the armrest vertical and the corner of the seat, as you don't want Unsightly Holes in the pattern. If, like mine, your chair had decorative nails in it before, you may find yourself nailing into existing holes. If your new nails aren't slightly longer than the old ones, use some wood glue in each hole that's loose. There is very little pressure on these nails so glue will be sufficient to keep them in place.
I forgot to take a picture showing the rest of the nails but really you can put them in however you want.