I do a lot of DIY and find the numbers and lines disappear from the outside of syringes pretty quickly. So what I do now is take a small, sharp knife and notch half and whole number marks. When all the printing on the syringe is gone, I run a sharpie down the notched "side", then wipe with a paper towel. The ink in the notches stays, while the rest of the marker ink is washed away.
I'm also starting to cut measuring notches into my bottle and mixing tubes.
TBL36
I'm also starting to cut measuring notches into my bottle and mixing tubes.
TBL36