What paper types and weights can be used in the MF1538C cassette?

The cassette (Cassette 1) supports a wide range of paper types including Thin (60 g/m²), Plain (61–105 g/m²), Heavy (106–163 g/m²), Color, Recycled, Letterhead, Labels, and Bond paper. Paper weights of 164 g/m² and above (Heavy 4 and Heavy 5), as well as Envelopes and Postcards, can only be fed from the Multi-Purpose Tray. (Page 22–23)