Clean lines

I always use automotive masking tape. For a REALLY sharp, clean line,
cut strips of tape with a new #11 blade using a metal straightedge as a guide.
To prevent paint from bleeding under the tape, burnish it down real well or,
spray some clear along the tape edges and let it dry before shooting your color coat. There's bound to be different and possibly better ways to get the results you want, This is just one of the many.
Ray

I use Tamiya masking tape. If I need a really sharp edge, I cut it on a glass plate.

Using Bare Metal is good too!

Thanks guys. I was thinking of trying the Bare-Metal. I hadn't thought about about sealing the edges of masking tape with clear.

I don't think th eclear tape would help... another choice is to get Scotch Drafting tape... art and drafting stores would have it. It is masking tape with have the adhesive. It sticks well enough for painting, but pulls off easy -- I only recomment this if you are air-brushing light coats tho...

The Bare Metal will leave some residue behind, but it is easy to wipe it off.

i think he means clear coat...

Yes. Clear coat.

You might try low-tack masking tape (the blue stuff). It has worked well for me. -Ed

i use painters mate green the thin one cause its cheap and not much else...

It depends on what you want to mask, for large areas such as camo patterns I also like the low tack painter's tape, the blue stuff. It comes in several widths, and unless you burnish it with a ton of force it wont lift off the paint underneath it.

To mask canopies, I prefer bare metal foil. Sure it leaves a residue, but it comes of easily. And BMF is so easy to cut canopy frames out of.

Hope that helps,
N.