By popular request following the d12 bag, here it is: the d20 bag! Now you can make your very own icosahedron.
We’re making a pattern and kit for this project available in two sizes: darling and practical. The tiny one is just over three inches tall, and holds little things for you. The larger size is about five inches tall and will fit your phone, wallet and keys along with your dice.
There are a deceptively large number of parts to cut out, which is one of the main reasons that a kit makes sense here.
Our kit includes twenty canvas pieces, twenty iron-on stiffener triangles, twenty cotton liner pieces, a cord for the handle, a zipper, and iron-on numbers 1-20 in the lovely font BPreplay. The iron-on numbers are made from a cotton-poly blend which fuses as it is laser cut so that it won’t fray. Assembly takes a few hours and requires thread, needle, scissors, pins and an iron (for fabric, not solder). A sewing machine will make some parts go faster.
d20 bag instructions:
If you’re using your own materials, the small pattern is available here (26 kB PDF) and the large pattern is available here (24 kB PDF). The small bag takes a 9″ zipper, and the large bag takes a 14″ zipper. Depending on how you lay out your pieces, you’ll need about two square feet of fabric of each type, with a little less needed for the smaller bag.
There are two sizes of iron-on stiffener panels: little ones (eight of these) and bigger ones (twelve of these). The little ones are to allow clearance for the zipper. The standard allowance the sides of the triangles is about a quarter inch for the tiny bag and about three-eighths for the handbag. The smaller stiffeners that go next to the zippers have the same allowance on the two regular sides, and an additional quarter inch on the zipper side.
Place the stiffener with the plasticky side (may be very smooth like the back of the numbers or may be rough but have a distinctly plastic texture) against the canvas, and place a hot dry iron on the canvas side for 5-8 seconds.
Arrange your numbers and fuse them under the iron for 5-8 seconds.
The first set of pieces to sew together are the ten that form the band around the center of the bag. There will also be five pieces on the bottom and five pieces for the lid. Lay them out in the order you’ll want to sew them in, with all of the zipper sides (smaller stiffeners with wider margin on one side) aligned. There will be one triangle in that row of the normal size: that’s where the lid attaches to the bottom of the bag.
If sewing by machine, your zipper foot will help guide the stiffeners along.
Sew each piece until you’ve got all ten strung together.
The next thing is to sew the bottom five panels on.
Lay them over the sewn strip (on the non-zipper edge), overlapping the edges and sew straight across the whole batch.
You’ll also need to make the same shape with the liner material. Sew the pieces together with a 3/8″ allowance.
Follow the same pattern as for the bag body.
Once you have both done, it will be time to pin the zipper in place between the canvas and the liner. The zipper should be aligned fairly deeply so that the seam goes just below the intersection of the triangles.
Pin across the zipper and sew it in place.
Once the zipper is in place, close it and mark the triangle intersections with pins on the lid side of the zipper.
Pin the zipper edge pieces for the lid to the zipper with four more of the loose liner pieces.
Sew the zipper on and test it to make sure it can freely open and close.
Next, begin sewing the lid together. Start at the open end and sew toward the intersection at the zipper edge.
Sew the last lid piece in and attach it to the main body of the bag with the cord placed between the pieces.
Piece the canvas together before the liner, as the liner is more flexible and doesn’t need to be as exact.
Finish piecing the liner except for the last piece. Leave it loose so that you can turn the bag right side out.
Check the points of the canvas to see if any of them are loose, and close the gap if there is one by hand stitching.
Turn the lid right-side out.
Feed the canvas through the last opening in the liner to turn it right-side out as well. Check all of your points to make sure they’re neat before sewing the liner shut.
Pin the last flap of liner and sew it shut.
And that’s it!
As always, if you are inspired by our projects, we’d love to see the results in the Evil Mad Scientist flickr Auxiliary.
Updated August 3, 2009 to add zipper lengths, yardage and variations in stiffener adhesive texture.