When I looked out some of my postcards recently, I came across one I really love, which features a stamp with an image of a colourful round-bottomed flask demonstrating Isaac Newton's theories on the reflection, refraction and colour of light.
I thought it would be a fun challenge to try to recreate this image myself using coloured pencils, so here's how it went! I was mostly intrigued by the colours, so I decided to leave the writing off my version.
I started by drawing round a small dish with a pencil to form the main circular body of the flask, and added the top of the flask using lines drawn with a ruler.
After this I drew it freehand, starting off gently adding colour, then making it more intense.
And here's how it looked when it was finished!