I've used a variety of pigments, from deep red nail polish (wife almost killed me) to fluorescent orange paint (fumes almost killed me) on the 2-inch washers for marking Start, Mile split and Finish points on the last couple of courses I measured.
Short of investing in a digital camera (reference Pete's suggestion), is there a good, semi-permanent means of marking washers that will not infuriate the local constabulary or the spouse?
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