The benefits of acrylic over glass are that acrylic is lightweight, shatter resistant, and optically pure. Also, acrylic poster holders have optional ultraviolet radiation filters and non-glare matte finishing.
If the artwork is large enough, a glass frame may be too heavy for the frame molding, frame hardware and the wall. Because acrylic is lighter, transporting any artwork is also easier.
When moving a glass poster holder, the glass may shatter. Acrylic does not shatter, making it safer to use in high-activity areas.
Glass sometimes has a green tint, while acrylic is typically clearer. If a UV filter is applied, the acrylic has a yellow tint, but the filter does not deteriorate, as it may with glass.