I have always had good luck looking for it by calling it "cuff stuff". I think that may have been a brand name at one time (or currently?) but that is what I call it, and everyone seems to know what I am looking for. I try to match the fabric type to the "cuff stuff". You can also go to second hand stores or big box stores, and look for the shirts that are called "wife beaters" (skinny sleeveless T-shirts) they are usually made from this type of fabric. You can make quite a few bib necklines with one shirt. I have even used fabric pens to add designs to the neckline. Just be sure to set the ink before using.