The challenge was based on the theme of Pi.
Here's my tile - an Opus one today - before I added shading, highlights and more intense colour.
Here's the finished tile.
The colours, other than white (white wax pencil and white gel pen) and grey are all Kaiser Mist sprays in a range of colours.
Here's how I coloured my tile.
Step 1: I painted the Pi string on the tile with plain water and I sprayed several colours onto baking paper.
Step 2: I placed the baking paper onto the tile and rubbed it, focussing on the pre-wet parts of the tile.
Step 3: I carefully lifted the baking paper off. You can see the Pi shape emerging.
Step 4: I took off the excess paint with a paper towel.
Step 5: I Tangled the tile.
Step 6: I intensified some of the Tangles by using a combination of a paint brush dipped into the Mist bottle and a paint brush dipped into a water and Mist mix. That helped to blend the colours. And then added shade and highlights.
Hours of work which I'm very pleased with - the process and the outcome.