We cut a stencil from clear film for every of the 11 sizes needed for the upper portion of the shade:

Our stencils were tested on right size by using some stripes of clear glass.

Fifth and sixth row are a bit too large here and will be recut to a slightly smaller size.
 

Here all of the test pieces are in right shape.

They are placed on the new mold, which is covered with a small

layer of our GSE bees wax to keep them in the right position.