Artsy does not do what they say....
Artsy states that they will provide a certificate of authenticity for the works represented on their sites. In my interaction with them, they failed to provide a Certificate of Authenticity, and when I pushed them on it and withheld payment, they ceased to work to provide an industry accepted certificate of authenticity and stated that an opinion letter is as good as a COA. I am fighting this now. The actual gallery who presented the piece indicated that they would obtain a COA and provide that to me. Artsy stopped them from doing so... stating that there was no requirement. I do not trust Artsy. I do not recommend. Go through your normal gallery connections to ensure that you can have a good experience and get the documentation that you need to support your pieces.