What’s an ATC?
ATC stands for Artist Trading Card. They are small works of art or craft, generally two dimensional (though mixed media ATCs can have some texture to them), that measure 2.5″ x 3.5″ no more, no less. ATCs are always originals and one of a kind, some times they are sold, but you almost always get them through organized trades or one-on-one swaps. An ATC can be a drawing, painting, collage, needle point, mixed media, there is no limit on the medium, anything goes! They are almost always signed on the back and usually dated as well.
What’s an ACEO?
ACEO stands for Art (or Artist) Cards Editions and Originals and have the same size requirements as an ATC, except they are made in small runs or as prints. An ACEO can be in an open edition (no limit on the number printed) or limited edition (with a pre-set number created, with no more printed after that number has been met). They are some times signed and dated on the back, limited editions more often than open editions, and limited editions are usually numbered, ie: 1/100.
I hope this is helpful! Please feel free to leave any questions in the comments section and I’ll do my best to answer them!