Adjusting for silkscreen dot gain...

I'm getting some issues with dot gain while printing shirts. I understand why it happens, but I'm having a bit of trouble on how to compensate for it at the software level.

Here's the main issue... if I'm creating something on my own, where nobody will see anything until the shirt comes out, I know to limit the colors so that only 10-90% are used. The problem comes from when I get files (either vectors or bitmaps) which use the full range from 0-100%.

Is there any kind of blanket command that can adjust the colors so that anything from 0-9% and 91-100% is bumped into the 10-90%?

If it makes any difference, I'm using AccuRip to print the film separations.