If you ever make fabric kits, such as for a block-of-the-month, for group projects, or for someone else to use, please don't ever use sticky labels to mark fabric numbers to match with a pattern. Over time (and not a very long time) they will get gummy, and leave a residue on the fabric that cannot be removed. The fabric might be completely unuseable, especially if it is in the smack-dab in the center of the piece. If you absolutely must use a sticker, just put it in a corner, or on the back, but not in the center of the piece!
The sticky labels can also fall off the fabric. Staples are no better, because they can rust, leave holes in the fabric, and are difficult to remove without a tool.
If you ever purchase a kit with stickers on the fabrics, get the stickers OFF the fabric ASAP and re-label your fabrics some other way until you are ready to use them.
Recently I bought a block-of-the-month set -- a beautiful design with great fabrics -- second hand from someone who collected them all for that year. Every piece of fabric had a huge label, slapped down in the middle of each piece. Here is a solid black piece, where the sticky label left residue.
So I went through all the fabrics, for the whole year, removed the big sticky labels, cut each one down to minimum size, and put them in corners. Here's hoping the fabrics will all be useable. (And glad I have stash to substitute.)
Here are some ideas to use instead:
* Lay the fabrics staggered far enough apart to see the labels, and take a digital photo, close enough that you can still read the labels. Print the photo and remove the labels.
* Clip off a small piece of the fabric, and glue or staple each fabric to a paper next to its label.
* If you are making kits, provide a color copy of this paper - well worth the extra few pennies.
* A full-color page of numbered swatches with fabric measurements can be used for assembling kits. The same fabric key, if included in a pattern, can be used by the quilter for fabric shopping or pulling from stash.