Day and Night Blind The structure of the shade fabric is mainly divided into straight grain and twill. Generally, straight grain fabric has better visual clarity. Twill fabric is not as good as straight grain fabric, but the glare control effect is good. Twill fabrics can gently introduce light into the room according to different heights and angles of the sun in the morning, noon and evening. Compared with straight-grained fabrics, the pores on the twilled fabric can effectively cut the light and let the light enter the room evenly. The square holes on the straight-grained fabric will produce square bright spots when the sun shines. If the openness of the straight grain fabric is too large, then when the sun is shining, it will make people feel dazzled.