Why we stretch came before we cut it

Lead came comes off the mill soft and slightly springy, and if you glaze with it in that state the panel will be a millimetre or two out by the time you have finished, because every piece has relaxed a different amount.

So it goes in the vice, and it gets pulled — a metre and a half of came stretched perhaps thirty millimetres. That takes the spring out of it, work-hardens it slightly, and straightens the heart. Came that has been stretched cuts cleanly with a lead knife instead of crushing, and it holds the line you put it on.

It takes about forty minutes to stretch enough lead for a day’s glazing and there is no version of this job where that forty minutes is wasted.