well, no... "Illuminati" means "illiminated (ones/things)". It's the writeups which are being illuminated. The people doing it would be illuminatores.

I believe the term for those who copied manuscripts, often embellishing with illuminations, was scriba librarius, usually abbreviated as simply librarius. The plural would be librariis, apparently. (but IANALS)

Update: If instead we choose to take the word "Illuminati" as being Italian rather than Latin, then illuminators would be Illuminatori. Which maybe swings better in context.

Fnord.