At garage sales yesterday I found some interesting plastic square tiles that are 5.75" square (instead of the normal 3.5' square) and immediately jumped out as a possible teaching tool!
(For some reason in the photo the shading looks a pink tinge?) It is not pink! Everything is black and gray. This one is Fish Net, Laces, Hurry, Gingham, and what I call Hurricane Isak (lower right hand corner...have no idea what that one is called!).
The plastic squares had something like "baby on board" or something on them originally on one side. Maybe you were supposed to hang it somewhere in your car? Some of them have a tiny hole in one corner and others do not. I bought 5 for 50 cents. She had 100 of them and but most of them were bright yellow. I thought if I gessoed the back side of the white ones I'd have 10 surfaces to make demo Zentangles on. I am picking the easiest to teach.
The surface took Ultra Fine Sharpie just fine and also took pencil shading. Then I sprayed with two coats of matt clear acrylic spray so the shading would not rub off. I would never use my Micron pens on any surface except paper. It's only in the photo to give scale.
I am numbering the samples and keeping a record of the patterns on another sheet...this one is Onamato, Cadent, Hybred, and the Ribbon Aura.