Sometimes your pet or furniture knocks up or exposes fibers/yarn from below the rug and you need to shave them off. Below is a great video explaining how to do so. The WEFT is the strand or yarn, under the rug, that runs the length of rug. This is the structural integrity of the rug. You will see a weft every few centimeters.
Placing the correct size rug in your space is as important as choosing the right color or pattern. A rug that it is too small will shift the balance of the room unfavorably. A rug that is too big, especially in open floor plans, may put the area designations off. There are a few rules of thumb, but a picture says it better. Use these handy guides by Interior Designer Lisa Ferguson to make the best choice.