This is a technique I have been doing for years. Recently Cat Hand from Mixed Media Morsels did a video on it https://youtu.be/8myU_lw9DEA
Substrate - I used a shipping tag
Decorative paper - In this tutorial I used decorative scrapbook paper but you could use magazine pages, old paintings, gelli prints, or wrapping paper.
Paper trimmer - optional
Adhesive - A wet adhesive works the best. I used soft gel medium in matte
Patience - If you use a heat gun on this technique to heat up the drying time you run the risk of it bubbling so I suggest just letting it dry on its own.
1. Cut up several different pieces of paper into strips with scissors or a paper trimer
2. Cut up the strips of paper into triangles. I keep the triangles in piles separated by colors.
3. Color your substrate. I used a tag I was experimenting with stencils and watercolor but if you paint it in solid color such as white or black with took like a more traditional stone mosaic.
4. Using the wet adhesive adhere the paper triangle to the substrate. Make sure to leave space between each piece to create the mosaic look.
5. Seal with the wet adhesive and let it dry.