Species with dense areolations (small clear areas in the derm), such as Saissetia coffeae, may have quite a thick derm, even just after the final moult but, even then, the derm becomes much thicker with age (up to 10 times thicker than the venter), with the area within each areolation remaining quite thin, usually with a microduct.

The derm may also show other characteristic markings and structures. On some species, the derm has distinct polygonal reticulations throughout, these being partly thickened ridges along the lines of dorsal pores.