Making and Knowing
A minimal edition of BnF Ms Fr 640

[TOC] | [diplomatic]

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Printers’ letters

Those who make them, mix into the lead some nails nailheads & old horseshoes, & antimony which makes it all melt. This composition is strong for printing, &holds steadfast. It runs and is good for casting in lead.

Casting in copper

It is necessary that the box mold be well smooth & that it fits well also on the board where it sits, so that it holds firm & does not shift when one moulds. It is necessary that the sand be clean & well chosen and well reheated, & pulverised very finely on the marble, for the one that you want to put first on the medal, and when molding you press strongly. Guard against oiling your medal, for this would make it porous. Reheat slowly and reheat well, & let cool. Moisten your sand with wine boiled with elm root, and cast latten which comes out well, namely from the substance of the trebuschets and similar thin things. Make your cast broad & even if it is barely thick, it will not be worse off, but it will enter well in the mold. Cast from the foot of the medal, so that the face, further away from the heat, comes out better & sweetened from the violent heat. And if your box mold does not have vents, make some qu in the sand, which come, from the corners of the piece, to render themselves into the cast. Cast very hot, something that you will know, when you cast a little leftover substance in the one which has already been melted, & if it melts quickly, this is a sign it is fo well hot. At that time, invigorate the heat of your furnace with bellows of the right size, keeping the mouth of the furnace well covered with some big copper tile or other similar thing, which should be very red before you cast. When you want to cast, take your well red mollettes & the crooked iron as well, to clean the charcoals which are in your substance. Having cast, rub your work with a latten wirebrush. The grindings from sharpening large scissors & large knives is very good for copper.

at left middle margin

One believes it to be a great secret to add in it persicaire, which renders them soft as lead.Try to extract salts from it.