To me, these look like regular ol' pleats but with quite a lot of fabric between them. I thought cartridge pleats were round and looked as though they had padding inside to keep them round.

I have a serger, but I use it only for serging garment pieces before sewing. I would like to know how else I can use it.

Excellent article about fiber characteristics, but the title is too long. Leave off "for Plus-Sized Designs". The author describes the fibers but comes short of telling the plus-sized figure what fabrics to choose. There is more to fabric than fiber content - color, scale of the design. Runa is correct: this article applies to everyone. It is not specific to the plus-sized figure.