This project could be completed with any kind of 2-D (more on that concept later) art work. The basic idea is a flat piece of art with LEDs behind or on top of the work.
For the first one, I painted a simple watercolor which included white dots and tree trunks. The white was preserved with masking fluid which was rubbed off after the paint had dried.
Tracing paper was placed over the painting to mark where the LEDs would go.
The circuit was drawn on foam core, using the tracing paper as a guide for the placement of the LEDs.
A parallel circuit made of copper tape was placed on the foam core the the LEDs were soldered onto the tape. Note the break in the tape which will form the pressure switch.
The tracing paper was used again to mark the placement of the switch on the back of the watercolor painting.
Foam dots with double-sided adhesive were placed around the LEDs and the switch to hold the watercolor painting away from the foam core. The dots were ¼” inch tall.
The original plan was for the battery to be between the two layers, but I realized this would make it difficult to change the battery when the power was depleted. So I sliced through the foam care and threaded the tape through the slots to the back.
When the pressure is placed on the painting in the location of the switch, the circuit is completed and the LEDs light up. When the pressure is released the LEDs go out. The thickness of the watercolor paper and the layers of paint made it difficult to see the light unless the painting was viewed in a dimly lit room. A friend suggested cutting tiny holes in the paper. But I started to think about the quality of watercolor paper and how mistakes can be removed by scrubbing, sanding, or scraping. So this 2D work of art really had a bit of 3D depth to it, which might allow me to remedy the light problem. I took a little Exacto knife and scraped away layers of paint and paper until I was satisfied with the thickness of the paper over each LED.
After doing this, the LEDs easily shone through the paper even in a well-lit room.