Here's a 100% version of the first panel from the Pimp Jesus comic, showing off the duo-shade style photoshop patterns at full size.

Light Tint - diagonal lines.
Dark Tint - crisscross lines (created by flipping the light tint and multiplying)
Dot Tint - crisscross lines (created by flipping the light tint and screening)

There's enough info here that anyone interested should be able to recreate the patterns themselves.

It's a lot cleaner to do it this way, than with the old developer bottles, that's for sure.