Lumi - Photochromic Dye

Lumi set and spray adhesive

Turns out none of these are good choices of material for the lumi

They block off very little light, as a result, the pattern is barely visible

Place transparency, object, stencil, etc over surface

Oh it also is a good idea to place a piece of clear acrylic on top to stop the wind from blowing the transparency, stencil, object away

Apply a layer of the dye

Let it sit in the sun for 10 min
You will see the color becoming more and more visible

Try to rinse as much of the dye off as possible
Use detergent will help

3D printed piece
It was pretty solid so it blocked off some of the sunlight. But the result is somewhat visible

The key is that the transparencies must adhere to the material (fabric wood etc) otherwise it will not block off all the uv light therefore creating blurry image