Per GM-Fial's post of 5/28/02 in the GM Announcements folder #70 "Enchancements to the Smoke Images"

<<There is a skill involved with images with five levels of images and six levels of skill. The sixth level allows for the teaching of the skill. The best a non-Olvi can hope to obtain is 3rd level, 2nd level for Skra and Prydaen, 1st level for Rakash in moonskin. Once you reach your highest skill level no more experience is awarded. Each smoke image has its own experience counter.>>

--aka Mykk