Which paint quality is most suitable for very fine poster-colour lettering?

Correct answer: Moderately thick and controllably flowing

The governing concept is paint consistency and brush control. Fine lettering needs a mixture that flows smoothly from the brush but is thick enough to hold a narrow line without spreading or forming blobs. A very watery mixture runs and loses edge control; a dry, grainy mixture breaks the stroke; and an excessively thick mixture drags, skips, and makes delicate curves difficult. Testing on scrap paper helps confirm the consistency.