Measure the width and height of the sand painting using a tape measure. Be careful not to disturb the sand surface of the painting.
Cut the dimensions of the painting into the center of a piece of matting board using an X-acto knife. Ensure that the matting is flush along all sides of the sand painting
Cut a piece of cardboard with scissors to fit behind the matting. The cardboard should be the exact dimensions of the entire piece of matting.
Glue the cardboard to the matting, then place double-sided tape on the back of the sand painting.
Press the sand painting onto the cardboard in the center of the matting. The flush sides of the cut matting and the double-sided tape will secure the painting into position firmly.
Slide the matted painting into a glass frame of your choice. Ensure that you choose a frame that fits the dimensions of the matting.