Most laboratories will choose to order microarrays from a commercial vendor; however, microarray printing is sufficiently straightforward that even small laboratories with extensive microarray needs may find it cost-effective and worth the effort to produce their own microarrays. Printing microarrays requires a spotting robot. For typical microarrays, oligonucleotides are distributed into 384-well plates and printed to polylysine-coated microarray slides. The details of a printing protocol vary depending on the robot being used; thus, follow the manufacturer’s instructions. However, a typical workflow using a robot equipped with contact steel quill pins is provided in this protocol.