But is difficult to do it?
Here is my reply:
The zipper pencil case was easy to make. I used 10 zips for one pencil case. I put 2 zips next to each other. One zip opening at the top, the other zip opening at the bottom. I used a 3 step zigzag stitch (width 5.0, length 0.3 on my Elna machine). I slightly overlapped the edges of the zips and stitched them together. I did 5 pairs like this and then stitched the 5 pairs together. Then I sewed the circles on the 2 ends, making sure one of the zips was open a little bit so I could turn it inside out. The circles were cut out of some pre-quilted fabric with a diameter of
Amazingly, the cloth part of the zips were not all the exact same length as you can see in the picture: