This is a 4 inch X 4 inch X 1/8th inch (101X101X3mm) Rigid Heddle insert. It is designed to be stack-able end to end to obtain the desired width. If your heddle is not a multiple of 4 inch units then you can easily cut the final one to the desired length with a razor saw. This is a very tight weave and I don't know how anyone would get their yarn through the tiny spacing and holes. I did print it and it prints very well using PLA and a thickness of .2