My master's thesis is based on tactile detection of surface defects in wood surfaces. I am using standardized 20cm disks made from different wood species as samples for my system.
The control samples are trivial to make by just sanding a defect-free piece of wood properly. The defect samples are where I'm facing issues:
Given that tools are (hopefully) designed to minimize defects as much as possible, it's not exactly easy to produce defects in a controlled and intentional way. Some types are easy (Scratches, dents caused by impacts, over-agressive sanding, etc.), but others like torn/fuzzy/raised grain, chip marks, knife burn, saw marks, aren't.
How can I intentionally produce surface defects (without neglecting safety)?
Intentionally damaging (inexpensive) cutting tools like saw blades is an option.