A good way to test the material is to slightly burn its surface with a match, thus producing a black spot. If the wool is good the singed part can be brushed off without leaving the slightest trace of the burn. The smell of the burnt wool will also easily be recognized. Ascertain the relative strength of the material, making sure that the warp is the heaviest and strongest, the pile next and the woof the lightest. If the warp is lighter than the pile it will break easily or if the warp is light and the weaving loose it will pucker. Rugs whose foundation threads are dry and rotten from age are worthless. In such pieces the woof threads, which are the lightest, will break in seams along the line of the warp when slightly twisted.
Examine the selvage. It will often indicate the method of its manufacture, showing whether it is closely or loosely woven, for the selvage is a continuation of the groundwork of the rug itself. Also notice the material, whether of hair, wool or cotton. Separate the pile and examine the woof, noting the number of threads between each row of knots. If possible pull one of them out. In the cheaper grade of rugs you will often find two strands of cotton and one of wool twisted together. Such rugs are very likely some time to bunch up, especially if washed. See if the selvage or warp threads on the sides are broken in places. If so it would be an unwise choice. Now turn the rug over and view it from the back, noting whether repairs have been made and, if so, to what extent. View it from the back with the light shining into the pile to see if there are any moths. Pat it and knock out the dust. In some instances you will be surprised how thoroughly impregnated it will be with the dust of many lands and how much more attractive the colors are after such a patting. Rub your hand over the surface with the nap. If the wool is of a fine quality a feeling of electric smoothness will result, such as is experienced when stroking the back of a cat in cold weather.
Finally, before coming to a decision regarding its purchase, have it sent to your home for a few days. There you can study it more leisurely and may get an idea as to whether or not you would soon tire of the designs or colors. While you have it there do not forget to take soap, water and a stiff brush and scrub well some portion of it, selecting a part where some bright color such as green, blue or red joins a white. After the rug has thoroughly dried notice whether or not the white has taken any of the other colors. If so, they are aniline.