This 39” BEST lightweight stretcher bar is a good choice for art instruction, and white pine is a sustainable wood that is a good option for these lightweight stretcher bars. These stretcher bars are durable and high quality and will exceed your expectations. They provide great support for your small canvases and they work well for classroom instruction, for art students, and for artists in training. Veteran artists will also appreciate the cost and durability of these stretcher bars for their smaller works of art. Not intended for use on very large paintings, as heavy duty stretcher bars normally work better.