As my trial of photoshop is coming to an end. I have hunted down OpenCanvas 1.1. I downloaded it and frankly I love the watercolour brush. But, the layers...Multiply layer will not let me paint lighter colours over the top of darker ones. Add Layer and subtract layer just drive me crazy...Is there a way I can just get normal layers? Like in photoshop, or am I confined to a single layer to paint? (granted that would be a good way to learn)

Thanks.