Lead-block chasing is a traditional repousse-and-chasing technique in which the metal sheet being worked is laid on or held against a slab of soft lead, which serves as a yielding support: the lead deforms locally under the chasing punch, allowing the punch to drive the metal into deep relief without cracking it or springing it back to flat. The technique has been documented continuously in European silversmithing and jewellery practice from at least the medieval period and is still in use, although for health reasons it is now more often replaced by chasing pitch (a mixture of pitch, plaster of Paris and tallow) for fine work, and by polymer compounds in some modern workshops.

The procedure is straightforward. A flat slab of soft lead (commonly 6-12 mm thick, set into a steel pan or wooden frame) is prepared by lightly hammering its surface to remove any oxide and bring it to a level. The metal sheet to be chased, which may be silver, gold, copper or brass, is laid on the lead and held in place either by friction or by a few small staples around its perimeter. The chaser then drives the punch from above, with the lead yielding locally beneath the work to absorb the punch energy and to support the back of the deformed metal. After the front-side chasing is finished, the work is turned over and details are pushed back from the reverse using repousse punches, again backed by the lead.

The principal advantage of lead over chasing pitch is that lead is non-flammable, does not require warming with a torch to soften it, and can be used in a workshop without ventilation provisions for pitch fumes. The principal disadvantage, and the reason for its modern decline, is occupational lead exposure: chasing pitch fume contains organic volatiles but no heavy metal, while lead-block chasing produces fine lead dust and lead-contaminated swarf that must be managed with appropriate PPE and waste-handling. For this reason most contemporary workshops have moved to chasing pitch or to engineered substitutes (cerrobend low-melting alloy, certain dense polymers) for general work, retaining lead only for specific niche applications where its specific deformation characteristics are required.