After reading this brilliant post, I thought Bubs would have fun with milk marbling. It's easy to set up and highly entertaining.
A cotton bud
Dish washing liquid
Good quality paper (optional)
We poured enough milk to just about cover the large dish. Bubs then squeezed a few drops of food colouring into the milk at random spots.
The magic occurs when you dip the cotton bud into dish washing liquid and gently touch the food colouring with the tip of the cotton bud. Right before your eyes, the food colouring just wooshes into beautiful patterns.
There's a proper scientific theory for this that I'm still struggling to comprehend myself. It has something to do with milk being fat ... and dish washing liquid breaks up grease? So it sends all the colours whizzing away?
If you want to preserve the pretty marbling effect, use a piece of good quality paper and gently press it onto the milk and colours. We didn't get so much of a circular marbling because the milk was running though we did end up with a very abstract, gorgeous effect that I can't stop staring at. The original blog post recommended watercolour paper but it was too expensive so we used a better grade of drawing block that could withstand the gentle soaking.
The original blog post also cautioned that some people found that the paper dipped in milk had a funny scent to it and also recommended almond milk instead. We found that after leaving the paper under the blistering hot Malaysian sun, all the pieces dried fully and there wasn't any smell.