Red and blue markers.
The verso page was cut out around the drawing of plant forms and glued down onto the previous page, where Sharpie marker bleedthrough from the previous drawing is visible.
The recto page was drawn from a tiny advertisement at the back of an old McCall’s Needlework magazine from the late 60s or early 70s, text “Mrs Virginia Wareheim used her Fabricon Reweaving earnings to help put her two boys through college”. The Fabricon Reweaver was some kind of tool for mending wool fabrics, with two little hooky things for pulling strands back into place. When I was cleaning out my Gramma’s sewing room after she died, I found one of them in a drawer of her sewing machine table. I still have it but have never tried fixing anything with it.