I've seen various methods posted on BPL for marking measurements on pots and mugs. I didn't have all the equipment that some used, so I modified my approach a little. I thought I'd share it with as some might find it helpful.
Equipment used:
1/8" diameter dowel rod
2" diameter dowel rod
1" X 1/2" piece of scrap wood
small metal file
small wood rasp file
1 oz syringe
3" C-clamp
old beat up regular screwdriver
sharpie marker
ruler with 1/64" markings
regular claw hammer
Steps:
file all edges of screwdriver blade round with metal file
file a 1" wide flat section into the 2" diameter dowel rod with rasp file (for more stable purchase onto work table)
file the edge of the 2" dowel that will meet up with the inside curve of your pot or mug so you can press it flat against the wall
use syringe to fill mug in 2 oz increments then insert 1/8" diameter dowel into water
mark the spot of the wet /dry line in each of the 2 oz increments onto the dowel
once done with that step, transfer the markings to the scrap wood, subtracting 1/32" height from each marking to compensate for the diameter of the dowel rod
use the ruler and sharpie to make a vertical line where you want your indentations to be
mark your 2 oz increments across that line
mount the dowel with the flat side down on the work table with the C-clamp and secure in place
mark the center line on your screwdriver with the sharpie
place your pot or mug over the dowel rod and line up the screwdriver with the cross marks you made, paying attention to line up the vertical mark on the pot with the center line on the screwdriver
with the screwdriver in position, hit the back of the screwdriver with the hammer with a medium amount of force
*** IMPORTANT: Take your time! DO NOT hit it too hard! If you make the indentations too deep it will split the wall of your pot.
Continue repositioning the screwdriver so you hit the same spot and whack it again
repeat this process until you can clearly see the indentation from the inside of the pot
once satisfied with that indentation, start on the next
when finished, use a green scrubber pad and rubbing alcohol to remove the sharpie marks
the marks will not completely rub off, but over time will disappear
