Engraving (specifically, laser etching) is available on Leatherman wholesale orders through the form linked here.

There are two engraving options:

1) Text only: Straight letter engraving is limited to letters and numbers in specific fonts.  The size and shape of the tool limit what can be engraved.  Full-sized tools can generally hold about 16 characters.  More characters can fit, but the greater the number of characters, the smaller the text. See this chart for more specifics.

2) Logo (with or without text): Electro etch engraving can use camera-ready artwork to produce a logo.  Long, thin logos work much better than square logos (because the height of the engraved area limits the overall size of the image on the tool).  Logos with bold strokes work better than logos with great detail.

Fees and lead times are available here.