*The Cambridge English Dictionary defines a "Triptych" as one piece of art consisting of three paintings connected in a way that the outer two pieces can fold inward toward the central one that is larger. Many examples may be viewed with a Google search for Triptych images.
*Webster's New World Dictionary describes it as a group of three panels with pictures which may be hinged.
|Three separate pieces before being attached with Washi Tape|
|Collage over Acrylic Paints|
|Top view of folded Triptych|
|One piece tri-fold (junk mail) base with collage over alcohol inks background|
|3 pieces junk mail (back of Triptych) attached with Washi Tape|
Whatever your approach, I do suggest that all three parts of your art be attached in some way rather than separate, and that the theme/design on all three pieces be related to give continuity.
Media/techniques may include paint, ink, marker, rubber stamping, stitching, (light collage) etc.