The term "percale", once synonymous with the highest quality bed linens, is now used to refer to any bed linen with at least 180-thread count. Luxury bed linens are now available with much higher thread counts. The highest thread count available today is 1020. In part, this is due to a change in the way thread count is calculated. For the purposes of thread count, two threads twisted together are counted as two threads instead of one, which was the case some years ago. Advances in loom technology have also made higher thread count fabrics easier to produce. To achieve a 1020 thread count, two sets of two twisted threads run vertically ("warp") while one set runs horizontally ("weft"). To remember which term refers to the horizontal direction, remember, "Weft to right."