Here's a painting in which I tried to do things you're not supposed to be able to do in watercolour - namely, taking things out, painting light over dark, using opaque paint. I may have got a bit more interested in the process than in the finished product - don't know. Need, as always, time to think about that. But I think it's more or less what I intended to do - not something one can ever be too confident of achieving in any medium.
There are tutors who will tell you all of the above "don'ts" in watercolour; adding, with insufferable smugness, "of course, we don't use white in watercolour" (or black). What they do tend to employ, however, is masking fluid - which I loathe; not only because it destroys brushes, but because it can give a dangerously cardboard cut-out look (although in the right hands, it can work brilliantly; I'm just a bit prejudiced).
Well in this painting, which for the moment we'll call The Path, I included detail and washed it out again - I defy you to find it. I didn't use white, and in fact rarely do, but did employ Naples Yellow, which contains white and is thus opaque, and mixed it with Cadmium Yellow, which is also more or less opaque (no watercolour is totally opaque, but these two are more so than most). And using these opaque yellows, I painted light over dark. I did plan the painting - so didn't just slosh the paint on and hope for the best. But I like to think I broke most of the purists' rules, without using any kind of masking.
Sheer devilment - I do hate to be told what I can and can't do, in painting and in anything else.
This is, of course, a watercolour, on Bockingford 38 by 28cm 300gsm Rough.