Hi Paulo, based on my experience, selling painting needs some sort of connection between the seller and the buyer.
Try creating a proper Instagram Account and make it your personal digital "gallery". Under every painting, put the title of painting, short story about it, media used, the painting dimensions and link to your Ebay/Etsy/any popular marketplace in your country.
Last but not least, use relevant hashtags and create IG Ads (promoted post) on those particular paintings, and pick your market target e.g. living in same country as you, age, gender, interested in art and paintings, etc.
Hope that help. All the best.
Publicada el 04/06/pm