https://zartart.com.au/zartstatic/page/scratch-board-patterns-texture-exploration



https://www.artistsnetwork.com/art-mediums/drawing/scratchboard-strokes-12-critical-effects/


https://www.artistsnetwork.com/art-mediums/drawing/scratchboard-strokes-12-critical-effects/


https://arthive.com/encyclopedia/89~Scratchboard





http://www.thomasfluharty.com/store-originals/beaker-original-scratchboard-8x10


https://www.boardtoart.net/listing/534924051/ostrich-scratchboard-one-of-a-kind-ozzie