I would enjoy making an ATC with my favourite colour.
Hi Anne-Marie, you don't have to sign up anyplace, but you may want to review Elisha's opening post for some guidelines. Just in case you need more info, I copied and pasted this from an older post:
Create your ATC with your interpretation of the theme. Your original ATC file should be 3.5 inches x 2.5 inches or 1050 pixels x 750 pixels (can be portrait or landscape orientation) at 300 pixels per inch. Be sure to sign and date your. Post your ATC to the gallery here, as well, to share with all of our members.
For uploading to the gallery, save a copy of your ATC at 72 dpi jpeg, then upload. Be sure to share the link in the current ATC thread so we can leave you some love.
Let us know if you have any more questions - we'd love to have you join in!