In the last exercise, painting the flower, the frisket was cut in a process of
elimination. You removed area number 5 and painted it, then removed area number 4 and
painted it without replacing frisket film number 5. This was continued until the entire
process was completed achromatically. Then you sprayed a transparent color over this
rendering to develop the image.
This procedure is fine as long as all the petals are
meant to be the same color. However, if you were to paint petals number 5 red and petals
number 4 blue, you would have to replace the frisket film over number 5 before painting
number 4. This is to prevent one color from drifting into another. Replacing frisket film
in exact registration can be extremely difficult. The slightest shift in registration when
replacing the frisket will cause paint to fill in the gap and leave a line where you don't
want one or possibly cover some of the white paper on an adjoining area so no paint can be
received, thus leaving a white area in the rendering.
To assure registration when replacing frisket film, use a simple process called a
"flap system." Here's how to do it:
Cut the areas of frisket film you wish to render. When all areas are cut, take a small
piece of drafting tape and lay it over a small area of the cut (half of the tape on the
frisket you will lift and the other half on the frisket that stays in place).
When you lift up the frisket film to paint, it is now hinged with the tape. Simply fold
back the hinge so the frisket is out of the way and then paint the area. Once the paint is
dry, you can fit the flap of frisket back into place without any shift in its
registration. This procedure can be continued, picking up the frisket and dropping it back
into place until the entire rendering is complete.
TIP: When the piece of frisket is flapped back out of the way, the
adhesive side is facing you. To prevent painting the adhesive side, take a small piece of
the frisket backing paper and cover it. That way, when you airbrush, paint will not go
onto the adhesive and ruin its tack. Practice this on the flower exercise. Hinge number
5s, lift them, paint the area, then fit back into place. Repeat this process for
areas 4, 3, 2 and 1.
The flap process will save you time and aggravation.