The following is a suggestion from an artist who uses the easel with drawing tablets. His issue was with small tablets falling through the center of the easel. Here is his solution.

Bill,
Attached is a photo of a couple of additions I made to accommodate how your easel is used for our botanical drawing classes.  Two aspects,

1. A sheet of Plexiglas (12”x16”, 1/8” thick) which doubles as a support for undersized sketch pads and use for rear illumination of transparencies.
2. A sill made of wood (0.5” high, 0.75” deep) to support undersized sketch pads.  I cut notches on the bottom for both your tabs as well as the “nails” to preserve the utility of your design.  The Plexiglas panel has the identical notches.

I just wanted to share this with you for possible use by you in future product applications.  Thanks again,  Doug J. Kapaa, HI

Thank you Doug!