Percale refers to a tight weave of the fabric; one yarn over, one yarn under. It produces a very strong, lightweight and breathable fabric with a (semi) matt finish. Due to the special washing this fabric is even smoother then regular cotton percale. An other huge advantage is that it's non-iron!
Thread count refers to the number of threads woven per inch. In general; the higher the thread count, the more denser and softer to the touch a fabric becomes, provided that high-quality cotton and single-ply thread is used. Since we follow these high standards, our 200 and 300 thread count fabrics already are of good quality and our 400 or 500 TC will be noticeably softer and slightly heavier.