Expressive quilts / Kumiko Sudo ; [illustrations by Michiko Sanford ; photography by Roland Hanselmann]. (OCLC #21077233)
The hybrid AACR2/RDA record for this piece has physical description:
300 __ ǂa 96 pages : ǂb chiefly color illustrations ; ǂc 28 cm
The physical details recorded in ǂb suggest that the volume is primarily made up of color illustrations; this is different from “illustrations (chiefly color)”, indicating that the illustrations (which are secondary) are mostly in color (described in RDA 18.104.22.168 on Recording Color Content).
I did not find an RDA rule for recording that a volume is “chiefly illustrations” (that would be similar to AACR2 2.5C5); this may be because it can be more precisely recorded in the Content Type:
300 __ ǂa 96 pages : ǂb color ; ǂc 28 cm 336 __ ǂa still image ǂb sti ǂ2 rdacontent 336 __ ǂa text ǂb txt ǂ2 rdacontent
(including that second one depending on how much text is in there among the image content, which is primary.)
I notice that even for books that are “all illustrations”, records tend to still include the word “illustrations” in 300ǂb. (What do you think – should it be there?)
Many catalogers also include a note like:
500 __ ǂa Chiefly illustrations. 500 __ ǂa All illustrations.