Here’s another fabulous top pro tip from illustration great Rick Lovell:
There is a huge variety of pre-made, hand-held masks for airbrushing on the market. Some specialty masks with specific shapes are worth paying for, but I’ve found that I can make my own masks very inexpensively that work for most day-to-day applications.
French curves are templates made out of rigid materials like metal, wood or plastic that draftsmen used to use to create a variety of smooth, precise curves. A Burmester set consists of three different templates that when used together, can create almost any compound curve you can imagine. They aren’t cheap, and they are usually found in a set of one particular size. They are also relatively thick and inflexible. Wouldn’t it be great if you could have a wide variety of sizes of French curves that were really cheap, and that could be bent and lifted off the surface for crisp-to-soft edges, or just thin enough to allow for really sharp edges that thick materials don’t allow?
Here’s how to do it. If you have a set of French curves already, use a photocopier to make copies at various sizes: 25%, 50%, 100%, 150% and 200% of the original sizes which will give you 5 sets to work with. Or, you can just go online and search for images of French Curves. Download the highest resolution graphic you can find and print it at the sizes listed above. This variety of sizes should provide you with just about any curve you will ever need to paint, large or small.
Finally, tape .005mil acetate over the photocopies or prints and carefully cut out the curves with an x-acto knife. With acetate, you don’t have to cut all the way through the material; just score it with a sharp knife, gently bend the acetate at the score line, at it will snap along the score creating a nice, clean edge. You can use Mylar, but it’s harder to cut and you have to cut all the way through; it won’t snap like acetate will. I have the 5 sets I made years ago out of acetate, and they are still good as new. I store them in a regular file folder in a flat file drawer, and when they get too opaque from lots of painting, I clean them with rubbing alcohol and a paper towel.