Laying in bed when my ankles hurt, I have too much time to think. This procedure could be done with any small square ruler. It has to have a right angle to be a hst, and any square will work. A person could make a regular hst and then using it as a pattern just place a piece of blue painters tape where the edge of the fabric should be, and continue following her directions. Living on a fixed income with no money to spare, I think this would work.