Use one lamp and move the crystal under it. A flat crystal throws a broad reflection. A domed crystal bends that reflection into a curve that travels as you turn the case. Pits show up as tiny dark points in the reflection. On the lug, a polished bevel should carry the lamp as one continuous line. A break in the line is a knock that was buffed on one side only. You do not need a loupe. You need the lamp and a slow turn. Write the surface as you see it. Do not convert the observation into a grade, and do not compare it to a piece in a display box.

How it differs

For the Cartier Tank, compare the diameter you can measure with the length from lug tip to lug tip. A wide bezel can make the dial look smaller than the case. Keep the comparison inside this case idea.

Common mods

On the Cartier Tank, people change the insert, the bracelet, or the hand set. Name the one part that was changed and leave the rest undescribed rather than guessing.

What to check on a used piece

Check the clasp position, the end-link gap, and whether the hands pass cleanly on the Cartier Tank. Write those three and ignore the sales line. These notes are not authentication and not a shop.

A library page is written by {Site}. A photo post is one person’s notes. Neither authenticates a watch, offers it for sale, or speaks for the name on the dial.