I hunted for weaving cards online and quickly learned how to make my own cards for card weaving via this Instructable: http://www.instructables.com/id/Make-Your-Own-Tablet-Weaving-Cards/. I made mine from a recycled deck of pinochle cards because they're much larger than regular plaing cards. The pinochle cards gave me weaving cards that measure 2-1/2" x 2-1/2" and fit my hands quite nicely.
Now, I like the playing card weaving cards well enough, but I've started getting into much more historic weaves and require sturdier weaving cards. This is why a new instructable has been born.
You will need:
Empty and washed cat litter containers with the labels removed (or some 2qt margerine tub lids)
a ruler with a good, straight edge
a good pair of sharp scissors
a Sharpie (this is the only thing that will write on this grade of plastic
a hole punch
Please forgive any line markings you see on the cards. I will try and scrub them off at a later point as they do not interfere with the use of the cards.