Weaving is one of mankind’s most ancient crafts, with a history dating back thousands of years. Most weaving is done on a loom, and looms come in various sizes and complexities. The simplest of looms is a rectangular wooden frame, much like a picture frame, that has vertical "warp" threads strung on it, and horizontal "weft" threads woven through the warp. Placemats are common woven items, and can be made with yarn, cotton, plant fiber or even paper pieces for loom-free woven disposable placemats.
Tie the end of the yarn around the bottom left of the loom, or, if the loom has pegs, onto the bottom left peg.
Warp the loom by wrapping the yarn around the loom from top to bottom, with 1/4 inch between each thread. If there are pegs, guide the yarn back and forth between the top and bottom pegs, so that there is a series of parallel vertical threads. For a placemat, warp the loom so that it is around 11 inches wide.
Thread the needle with yarn for the weft thread, then tie the end of the yarn to the bottom right warp thread, around 3 inches from the loom frame. Thread the needle through the warp threads in an ‘"under, over, under, over" pattern, until you reach the end. Pull the yarn through the warp threads after the needle, but not so tight that it distorts the end warp thread.
Thread the needle around the last warp thread, and go back along the warp threads in the same "under, over" pattern. This time warp threads that had the weft thread under them the first row, will have the weft thread over them in the second.
Continue in this manner, alternating the pattern each row. Push the weft threads in a downwards motion every couple of rows to compact the weaving.
Change colors by simply tying on a new color yarn to the end of the old color weft yarn and continue weaving.
Finish the weaving once it has reached around 14 inches length. Make sure there is around 3 inches of warp thread left at the top of the loom as well. Tie the end of the weft thread onto the last warp thread to secure the weaving.
Cut the warp threads off the loom. The warp threads can be trimmed to around 2 inches long and left loose, or pulled into bunches of around four warp threads and knotted at the base, or pulled into bunches of three or six and plaited to finish the placemat.