You may have heard of "high-density" such words. Number and density are important standard for measuring cloth. Higher the yarn, yarn is finer, more soft cloth. More than 30 pieces of cloth known as high.
A total number of lines per unit area and show that the number is the density of the fabric. There may be the same cloth came to the density difference (just don't look the same), in fact, simply because different per unit area. For example, Hing Ting CA product density: 200 yarns per square inch = 310 yarns/10 cm.
Practical advice: bed 40 yarn has been very good, 30 is not recommended. Density can be considered in more than 144 pieces of yarn per square inch, which is 230 yarns/10 cm.
Fabric printing and dyeing
Printing and dyeing is not the same as the now bed there are products such as printed, yarn dyed, plain, because of different ways of printing and dyeing, feel and colour fastness is quite different.
Practical advice: the bed will worry about fading or color will be a problem. Dyeing and finishing know-how is complicated, the easiest method is to choose the brand goods, currently there are some little-known brands on the market at any price to be more careful.