As an artist, I've participated in many group exhibitions and sales of art, and have organized and curated several as well. They are great ways to show your art and speak with potential buyers. Essentially, it can be the same as displaying your artwork in an Art Gallery. But what do the buyers expect of the artwork in an art show?
Original Art
Most buyers who go to an art show and sale are expecting original artwork - no reproductions. Most Art Galleries only show original artwork, so many art shows and sales are the same.
If you are participating in a community show or event that is
not specifically billed as an art show/sale, buyers would perhaps
expect that reproductions of all sorts (canvas, paper, gift items) may
also be available. A mixture of original and reproductions would be
acceptable in these cases.
Artist-Quality Supplies Used in Production
The supplies used in the production are of artist-quality. For example, when using acrylic paints, the artist would be expected to use artist-quality paints; therefore, craft paints in bottles from dollar stores or crafting shops are not acceptable. Neither are the lower priced student-grade paints. Most art supply stores clearly mark which paints are artist-quality. If they do not, you can certainly search the brands they sell online to determine if they are the student- or artist-quality versions.
An Art Gallery may ask you as the artist to certify you have used only artist-quality paints in the production of your artwork. The same should be applicable to an art show. buyers would expect your original artwork would be produced with high quality supplies. Art is an investment after all, and the value is expected to increase over time, not decrease as it would when inferior supplies are used (which can fade quickly or even crack).
Copyright of Artwork
Copyright of the final image of your original artwork is retained fully by the artist, unless express written consent is given. This means the buyer does not have the right to produce any sort of reproductions (for sale or give-aways) of your artwork.
Some buyers may also expect that the original artwork will not be available as reproductions. Although it is always nice to let purchasers know up front if you are currently selling reproductions of that image, or have intentions to do so in the future, you are not required to disclose this to the buyer.
So, if you are transitioning to selling your artwork and are participating in art shows and sales, you may want to keep the above points in mind before submitting any of your artwork in an art show.