Micro Mask?

I agree with Simon. I use it for canopy masking also, and it works great (not sure what brand I'm using). I have a tendency to leave mine on a lot longer than 3 days, just because I procrastinate and if you're doing a 3-color camo job then[/] Future [i]then decals [i]then[/] dullcote, you're up to a week easy (at least).

I am using Humbrol Maskol to fill in canopies once the framing is masked with Tamiya tape. This has worked really well on the last two projects even with being left for far longer than the 3 days recommended. Painting has been with the Humbrol enamels which I guess the Maskol is complimentary too. If you want to use the Micromask with tape for canopies I wouldn't expect too much of a problem as the edge is being formed by the tape and not the liquid and you don't have a base colour to pull up. Artists masking fluids would likely have an acrylic compatible fluid available from your local art supply store.

liquid masks that I've used really get a grip on acrylic. It's too hard to get it off. I can't remember how it acted on enamel. The one I currently have is Ambroid Ez mask. I really only use it to mask bare plastic sections... sometimes.