If you're looking for synonyms for the word "pastelist" - someone who works with pastels - then there are several options to choose from. One alternative might be "chalk artist" or "chalk pastel artist," which emphasizes the medium used. Another possibility is "soft pastel artist," which distinguishes pastels from their oil or hard counterparts. One less common but still valid option is "crayon artist," as pastels could be considered a type of crayon. Finally, one could simply use the more general term "artist" or specify a particular type of artist - for example, an impressionist or landscape artist who often works with pastels.