I love the look of mesh on layouts, but its really expensive for just a little bit. I found something that works just as good,....drywall tape! Its used for making repairs to drywall, you may have some laying around already. If not, it's really inexpensive.
It already has an adhesive backing, and it can be painted or inked or chalked to whatever color you want. You can tear it, distress it, thread ribbons through it and more. Another cool use for it is to use it for masking with ink. I put it down, then take an ink pad and dab over it, pull it up and you have a great pattern, good for a background or a photo mat or anything.
Its really cheap for a HUGE roll. You can get it any home improvement or hardware store. Lots of the big chain stores sell it also. I'm not sure on the acidity of it, though. You may want to check if that is a problem for you. I just place it away from direct contact with my photos.