Please give artists the option to block users who:
- abuse the artists,
- abuse the limited commission slots system,
- send unrelated images and links/spam,
- or ignore rules set by the artists (eg. sending NSFW/explicit images to strictly SFW artists),
so that the abusers cannot create new projects in the future/access the artist's page.
In order to prevent artists from abusing the blocking system for profit, it should be only available before any payment/project agreement between the artist and the client has been made.