Most Gerber PFs (the little cotton ones, not the ones with the padded centers) I've come across are birdseye, but it's a pretty cheap birdseye and therefore not terribly soft, and very thin. Most DSQ prefolds I've seen are twill. When it comes to higher quality fabrics, twill is a thinner fabric than birdseye. Twill also has more of a straight weave to it...Birdseye has a more complicated-looking weave to it (hard to describe, but it's not as plain as twill). Both are WONDERFUL in unbleached form, which I highly recommend. Don't let Gerber fabrics affect your opinion. I have DSQ birdseye flats, and birdseye material I've bought and used to make other dipes, and they are NOTHING like the Gerber stuff.
Mrs.Oz :, wife to Mr. Oz , mother to Boo : 2 years and Sissy 9 months.