The first thing, which should have been obvious but which I overlooked is - need more paint.
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Also, I knew that when you go larger you have to step away a lot, but I hadn't really factored it in as a habit. So I was kinda hit in the face with this fact, after lovingly painting the shadows and contours of a leaf for half the day and stepping back from it only to realise it did not work at all in terms of its surroundings. It is frustrating, after previously being able to work on something solidly to have to break your concentration to stand up periodically *
On that same note, painting with small brushes and building up shadows with tiny cross-hatched strokes wasn't working out either. I have now repainted over my original base and started to do very rough shapes of light and shade, not really caring about the details so much. I'll have to care about them later of course, but details to begin with were just terrible idea, especially when I had to paint over them all and felt awful that i'd invested so much time in them.
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I realised I need quality bigger brushes as well. I have a lot of very good tiny brushes and one or two dejected larger brushes. So since I had some money burning a hole in my pocket - and since I was feeling frustrated with progress - I went to the art store and bought the most expensive paint brush i've ever owned. A large, flat, part-sable brush which is absolutely beautiful and worth it's weight in gold.
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It holds paint better, it is incredibly soft and it never really disturbs the paint beneath even if that's still drying, it paints in even consistent strokes, there's never any unfortunate globules or bubbles going on. The lesson learned here is that although a bad workman might blame his tools, a good workman doesn't use bad tools.
On that same point - I always wondered why I had such a hard time replicating colours exactly. It never occured to me that it might be another case of bad tools
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Thanks all for excellent suggestions and comments on last post by the way. Every day i've been trying to study something, and I may try some life-drawing classes if I can find some which happen in the evening. Hope you all have a great weekend, i'm off to the hairdressers today (I'm frightened of them so wish me luck!). And also, it is stunningly hot here again, so i'll be doing a lot of walking around...I can barely wait.
If any of you have any tips for me about painting large then I would greatly appreciate hearing them!
*I managed a nifty solution to checking from a distance which doesn't involve standing up and breaking your concentration. I always have a mirror handy in any case (for checking a painting in reverse) and if you hold it at arms length you can check the painting from a distance much more easily (depending on the size of your image you could also position one behind you so that you could just turn round and check it)