PART THE FIFTH.
Chap. 104. In what manner the art of painting pictures should be acquired.
Know, that you cannot learn to paint in less time than that which I shall name to you. In the first place, you must study drawing for at least one year ; then you must remain with a master at the workshop for the space of six years at least, that you may learn all the parts and members of the art, - to grind colours, to boil down glues, to grind plaster (gesso), to acquire the practice of laying grounds on pictures (ingessare le ancone), to work in relief (relevare) y and to scrape (or smooth) the surface (radire), and to gild; afterwards to practise colouring, to adorn with mordants, paint cloths of gold, and paint on walls, for six more years, - drawing without intermission on holydays and workdays. And by this means you will acquire great experience. If you do otherwise, you will never attain perfection. There are many who say that you may learn the art without the assistance of a master. Do not believe them ; let this book be an example to you, studying it day and night. And if you do not study under some master, you will never be fit for any thing ; nor will you be able to shew your face among the masters.
Chap. 105. How to make paste of flour (colla di pasta o ver sugolo) (1).
Beginning to paint pictures in the name of the most holy Trinity, and always invoking this name, and that of the glorious Virgin Mary, we must first prepare a foundation, and this is made with various kinds of glue. There is a cement made of boiled paste, which is used by persons who make books, and is proper to fasten cards, and also to fix tin upon paper. It is used sometimes also when paper is to be glued together for the use of sculptors. This paste is made in the following manner. Fill a pipkin almost full of clean water, and make it warm. When it is just going to boil, shake some fine flour, a little at a time, into the pipkin, stirring it con- tinually with a small stick ; make it boil, but do not let it be too thick. Pour it out, and put it into a porringer. If you wish it to remain sweet, add some salt ; and use it when you want it.
Chap. 106. How to make glue for fastening stones together (I).
There is a cement proper for fastening stones, and this is made of any kind of glue, new wax, and pounded stone, strained and tempered together over the fire. First clean your stone, then heat it, and apply the glue. It will withstand air and water, and is used to fasten grind-stones and mill-stones.
Chap. 107. How to make cement for joining glass vessels.
There is a cement proper for joining broken glasses or jugs, or other beautiful vases of Damascus or Majolica (1). This is made of liquid varnish, a little white lead, and a little verdigris. Make it of the same colour as the glass ; if it be blue, add a little indigo ; if it be green, add more verdigris ; et sic de singulis. Grind these ingredients well together, as intimately as you can. Take the pieces of your broken vases, though they be in a thousand pieces, join them together with this glue ; and if you let them dry for the space of some months, sheltered from the sun and wind, you will find these vases stronger and better able to keep out the water than when they were whole.
Chap. 108. Howfish-ghie is to be used and dissolved.
There is a glue called fish-glue (colla di pesce, isinglass). This is prepared from many kinds of fish. If you put a piece of this to your mouth, and wet it, and then rub it a little on your vellum, or other cards, it will fasten them strongly together. When dissolved, it makes a good and most excellent cement for lutes, or other delicate works of paper, wood, and bone. When you put it over the fire, add for each piece of glue half a glass of clean water (1).
Chap. 109. How colla di caravella (I) is made, how dissolved, and for what purposes used.
There is a glue called colla di spicchi, which is made of the feet, sinews, and clippings of skins of goats (caravelli). This glue is made in January or March during the great cold or high winds, and is boiled with an equal quantity of water until it be reduced to less than half. Then pour it out into flat vessels, such as saucers for jelly, or basins. Let it remain one night ; the next morning cut it in slices, like bread, with a knife ; put the pieces on rush-mats to dry in the wind, without sun ; and it will become excellent glue. This glue is used by painters, by saddlers, and by many masters, as I shall hereafter tell you. It is good glue for wood, and many other things, of which we shall treat more fully when shewing how it is to be used, and in what manner for plaster, in tempering colours, making lutes, in inlaid works (tarsie), also to fasten wood, and a number of leaves (of books), in tempering plaster, in working with plaster in relief, and in many other things.
Chap. 110. Excellent glue to temper grounds for pictures.
There is a glue made from shavings of the skins of sheep and goats, and from the clippings of these skins. These are to be well washed, and laid in water for the space of one day to soften, before they are boiled down. Boil them until the quantity of water be reduced to one-third part; and when you have no glue (colla di spicchi) you may use this for mixing with the grounds of your pictures; and it is impossible to find better (1).
Chap. 111. Glue proper for tempering azures, and other colours.
There is a glue made of the parings of parchment. Let it boil in clean water until the water be reduced to about a third in quantity. It makes a glue as clear as a crystal, and is good for tempering dark blues ; and if you have to lay a flat tint of any colour not properly tempered, give it a coat of this size. Temper the colours again, and fix them ; you may varnish them if you please when used on pictures, and also those blues used on walls (1). This size is also good for mixing with grounds ; but it is naturally thin, and plaster which is to be afterwards gilded requires a richer kind of glue.
Chap. 1 12. To make a glue of lime and cheese (1).
There is a glue used by workers in wood which is made of cheese put into water to soften. Rub it down with a muller with both hands, adding a little quick lime. Apply it to the boards you wish to join, unite them, and fix them well together. And this is sufficient information to enable you to make many kinds of glue.