It was common for craftsmen to stamp tools with initials or name as proof of ownership, and the Dominys were no exception to this practice. Their initials and names have survived not only on the tools in the collection, but fortunately on some of the dies used to mark their tools. No record survives to show whether they made or purchased the dies. Each has a steel face into which the letters were cut. The dies used by Nathaniel IV and Felix Dominy have raised letters; the one used by Nathaniel V has incised letters.

Diemaking was a highly skilled occupation. The Dominy accounts do not provide any clue to the origin of these examples, but the holding blocks were undoubtedly made in their woodworking shop. In the Dominy shops these dies were primarily used to mark tools and clock parts. Frequently individual dies were used in combination to produce special number or letter effects.

The images below are a sample of the die in the Dominy Collection. To see all the die in the collection, please search Winterthur's museum online database