Known as the Omote. the top cover of the mat is usually made from woven igusa grass and there are a wide variety of mats to choose from depending on the look required and the budget available.
There is a wide range of top mats which have more with the higher qulaity Omote having a higher quality grass and more internal threads. Visually the difference between the mats can be hard to perceive but for areas where there is likely to be high traffic the higher quality mats will give longer service.
There is also a range of paper tatatmi omote which come in a variety of different colours.