I dived further into unknown watercolouring territory today when I painted my first clear glass and colourful marbles. I didn't have any real difficulties with the marbles except for those inside the jar because even the original image seemed unreal. I, more or less, followed a tutorial (link on External Links page) on YouTube for this but my skill and eyesight are obviously not as good as the artist Shaji Chaladan's. He's amazing and deserves a bigger following.
What I found really difficult was the screw top of the jar and in the end had to stop fiddling around with it as I couldn't see what I was doing. I painted it in my Strathmore watercolour journal using Roman Szmal paint. It looks quite pretty in the journal.