As a fine artist, you’re entitled to the contact information of people who purchase your work through consignment.
Specifically, G.L. 104A Section 2(c) states:
If the consignor is the creator of the work of fine art . . . the consignee shall disclose the name and contact information of the purchaser of the work of fine art to the consignor with payment of the funds owed to the consignor.
This information is often difficult or impossible to obtain long after the fact when developing a catalogue, so be sure to get this information from galleries early on.