When you take one of my workshops one of the exercises I teach is to work wet-into-wet on a sheet of thin watercolor paper that is placed wet on a sheet of plexiglass. The reason for this lesson is to teach students to control the amount of pigment they need to control their watercolor wash. It is also great because it turns 90lb paper into 900lb paper depending on
how thick your plexiglass is.
This technique is very effective because the sheet of paper will stay wet for a long period of time, giving the student time to learn how much pigment is needed to control their brush strokes.
Normally with this lesson I have my students use a quarter sheet of 90lb paper that measures 11" x 15". The demonstration I did below was twice that size and at first it had me a little worried that it would dry before I
could finish the first wet-into-wet wash. I am happy to report the paper stayed wet the entire time and there was no problems with the big size affecting the technique.
When soaking the paper and then appling it to the plexiglass make sure there are no air pockets under the paper. You can usually brush the air pockets to the edge to get rid of them. Try to cover the paper with an even coat of water. This can be done by brushing back and forth all over the paper
with a large brush.
Make sure you have fresh paint on your palette so you can pick up enough pigment so you can control the amount of pigment needed to achieve softness and hardness on the edges.
Plexiglass can be purchased at most building supply stores or hardware stores. I have found plexiglass in framed work of art at Goodwill or a resale shop, usually you can tell it is plexiglass because of the scratches on the surface.
It's a great
lesson, give it a try.