I've done several art cards but prefer the small format art because there is more flexibility in the size, and you can use more variety in the surface you select. Some surfaces create problems for the collector of ACEOs.
Small format art (SFA) offers mixed media, collage, and fiber art, as well as photographic, watercolor, oil, acrylic, and pastel original works. One thing I like is that you don't find the prints of original work in the SFA area like you do with ACEO's.
Here are a few examples I found on Artfire, Zibbet, and Etsy. I hope you enjoy them, and maybe you will find one just right for your space.
Thank you for looking at my little gallery of small format art.
Pepper, Pep, Helmet Head