Silk-on-silk (silk pile on silk warp and weft): This is the most intricate type of carpet, featuring a very fine weave. Knot counts on some superior-quality "silk-on-silk" rugs can be as high as 28×28 knots/cm2. Knot counts for silk carpets intended for floor coverings should be no greater than 100 knots per square cm, or 10×10 knots/cm2. Carpets woven with a knot count greater than 10×10 knots/cm2 are intended to be used as a wall or pillow tapestry, because their fabric is less resistant to mechanical stress. These very fine, intricately-woven rugs and carpets are usually no larger than 3×3 m.