It's 9 x 12 = 108 unique caps. No repeats. I don't know if I should be impressed or worried for our livers. My excuse is that we have been collecting caps for years and try new things all the time.
I fiddled with the placement of a few caps within the columns but this was the overall color change- red orange yellow gold white green blue black.
The finished tray:
The steps are simple: use a hot glue gun to glue down all the caps. Mix up some grout and press it between all the caps. Use a damp cloth to wipe clean the surface of the caps and make them shiny again. When the grout is dry, mix epoxy resin and pour it over everything. Blow on the surface of the resin to pop bubbles and use a toothpick to pick up errant bits of fur that have settled on the surface. Leave in a shut room overnight.
Each tray is a learning experience for me and this time I learned not to scrub the caps so much. This was the largest tray I've done and I didn't have enough grout to do the entire thing at once. I put down what grout I had and using paper towels, I cleaned around each cap. Cleaning, rubbing, essentially exfoliated each cap without realizing that I was scrubbing away the design. I bought more grout and did it all again. I stepped back and wondered why the colors didn't look so vibrant; then I noticed that I was scrubbing it all off! You can see around many of the caps in the close-up picture that the design has been rubbed off around the edge. It's not so bad- it gives it more of a... distressed or antique look but NEXT time I'll make sure I have enough grout and do this step without scrub, scrub, scrubbing away a little of each cap's color.
I love showing this tray to people because they're eyes dart around- reading each cap, recognizing some, wondering what others are. It's a pretty fun functional piece of art. We're keeping this one!