I hear a lot about oil pastel not being forgiving, or not allowing you to correct your mistakes. Not true. Well, mostly not true. If you wanted to keep the support white, or whatever the background color is, and you put, say, a black line through it, that could be a problem. I've done similar things and have usually found a way out. But my work is fraught with mistakes that I've managed to cover up. Just scrape or wipe the mistake away as much as possible and lay the color you want on top of it. Most times, though, I don't even do any wiping or scraping. You might want to let it dry a little before you do any layering. Of course, it can get ridiculous if one has layer after layer on the support. (Which I admit I sometimes do.)
I guess I'm saying this because there shouldn't be anything scary about using oil pastels - just take the plunge - they are so wonderful! One thing, though, I use mostly Senneliers and they are great for layering because they can cover anything. But I have also layered with the less gooey ones and they worked fine - just need a bit more wiping/scraping. Thanks for stopping by!