Hi! I have also encountered this question. My choice is cotton for the summer. It breathes, does not heat, and is really comfortable. But in the winter it is better to take viscose or a mixture of fabrics to make it warmer. I recently found a good store with different fabrics for hijabs, there you can choose for both cold and warm weather. I can recommend looking here: https://www.amanis.com/ . There are fabrics that are perfect for different seasons and provide good comfort all day long!

Cotton is great for summer, of course, but I also like jacquard. It's not too hot, but it holds its shape, which is important when you want your hijab to look neat. I shop in different places, but I also looked at Amanis. The selection is really good there, and the delivery is fast. In general, I recommend trying different fabrics depending on the weather and how long you wear your hijab during the day.