The body obtains vitamin A in two ways. One is by manufacturing it from carotene, a vitamin precursor found in such vegetables as carrots, broccoli, squash, spinach, kale, and sweet potatoes. The other is by absorbing ready-made vitamin A from plant-eating organisms.
It takes a really good glue to hold picture frames together. The common glues that you see in hardware stores just don't cut it. Picture frames glued up with these glues will snap apart very easily. Because these picture frame clamps are not professional vises, it is even more important to use a really good glue.
Best Answer: Well, if you're referring to the little wooden or plastic triangle thingies that come along with a pre-stretched artist's canvas, they are wedges that are meant to be hammered into the corners from the back to tighten up the canvas if it ever gets loose on the stretcher frame.Good luck!...âº. Source(s):hey are called stretcher keys. If your canvas loses tension you can put them in to make the surface more taught. A loose canvas can cause cracking or flaking in your paintings so its always best to keep the keys in case this happens.