Typical plastic ink cups are much to rigid and can damage the needle and splash ink out if the cup is touched. Silicon ink cups have a rubber feel to them and do not get damaged if one accidentally grazes the cup with a needle. These ink cups come in 2 sizes:
Large (100 piece): With the DermMicro HD pigments, one large ink cup can be enough to complete an entire SMP session.
Small (200 piece): The smaller ink cups are best used for smaller areas being covered like a scar, or to fill with skin toned pigment, like Complexion Correction for SMP removal.