Dictionarium polygraphicum. Gilding.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
GILDING is the art of spreading or covering a thing over with gold, either in leaf or liquid.

The art of Gilding was not unknown to the ancients; though it never arriv'd among them to the perfection to which the moderns have brought it.

Pliny relates, that the first Gilding that was seen at Rome was not till after the destruction of the city, in the time of the consulship of Lucius Mummius; at which time they began to gild the ceilings of their temples and palaces; the capitol being the first structure adorn'd with this inrichment.

He also adds, that luxury grew so hastily upon them, that in a little time you might see all even private and poor persons gild the very walls, vaults, &c. of their houses.

But we have this advantage of the ancients in the manner of using and applying the gold, the secret of painting in oil, lately discovered furnishes us with means of Gilding works, that will endure all the violences of time and weather; which was impracticable to the ancients.

They knew no way of laying the gold on bodies, that would not endure the fire; but with whites of eggs or size, neither of which will endure the water; so that they could only gild those things, which stood in such places as were sheltered from wet, and the humidity and moisture of the air.

The Greeks us’d a sort of composition for Gilding on wood, which they call'd leucopheum or leucophorum; which is describ'd as a sort of glutinous compound earth, which in all probability serv'd to make the gold stick and bear polishing.

But as to the particulars of this earth, its colour, ingredients, &c. naturalists and antiquaries are not agreed.

There are several methods of Gilding in use among us, as Gilding in water, Gilding in oil, Gilding by fire, &c.

The method of WATER GILDING.

Water Gilding requires more preparation than oil Gilding, and is chiefly on wooden works, and those made of stuc, and these too must be sheltered from the weather.

A size is us'd for this way of Gilding made of shreads, &c. of parchment, or gloves boil'd in water to the consistence of a gelly.

If the thing to be gilt be of wood, it is first wash’d with this size, boiling hot; and then set to dry, and afterwards with white paint, mix up with the same size.

Some use Spanish white for this purpose, and others plaister of Paris, well beaten and sifted.

This siz'd paint must be laid on with a stiff-brush; which is to be repeated seldomer or ostener, according to the nature of the work, as ten or twelve times in flat or smooth works; but seven or eight will be sufficient in pieces of sculpture.

In the former case they are apply'd by drawing the brush over the Work, in the latter by dabbing it.

When the whole is dry, they moisten it with fair water, and rub it over with several pieces of coarse linen, if it be on the flat; if not, they beat or switch it with several slips of the same linen tied to a little stick, to make it follow and enter all the cavities and depressures thereof.

Having thus finish'd the white, the next thing to be done is to colour it with yellow oker; but if it be a piece of sculpture in relievo, they first touch it up, and prepare the several parts which may have happened to have been disfigured by the small iron instruments, as gouges, chiffels, &c.

The oker us’d for this purpose, must be well ground and sifted, and mix’d up with the size beforementioned.

This colour is to be laid on hot; and in works of sculpture supplies the place of gold, which sometimes cannot be carried into all the depressures and cavities of the foliages and other ornaments.

A lay is also apply'd over this yellow; which serves for the ground on which the gold is to be laid; this lay is usually com pos'd of Armenian bole, blood-stone, black-lead, and a little fat; to which some add soap and oil of olives; others burnt-bread, bistre, antimony, glass of tin, butter and sugar-candy.

These ingredients being all ground together with hot size, three lays of this composition is apply'd upon the yellow, the one after the other has been dry'd; being cautious not to put any into the cavity of the work to hide the yellow.

The brush u'd for this purpose must be a soft one, and when the matter is become very dry, they go over it again with a stronger brush to rub it down, and take off the small grains that stick out; in order to facilitate the burnishing of the gold.

To be prepared for Gilding, you must have three sorts of pencils; one to wet, another to touch up and amend, and a third to flatten; also a Gilding cushion for spreading the leaves of gold on when taken out of the book. See CUSHION, a knife to cut them and a squirrel's tail fitted with a handle; or else a piece of fine soft stuff on a stick, to take them up directly and apply them.

You are first to begin with wetting your pencils; by which the last lay laid on with water is moistened, that it may the better receive and retain the gold. Then you are to lay the leaves of gold on the cushion, and if whole, you must take up with the squirrel's tail; but if in pieces, with the other instrument, or the knife wherewith they are cut, and lay and spread them gently on the parts of the work you had moistened before.

If the leaves (as they frequently do) happen to crack or break in laying on, these breaches must be made up with small bits of leaf taken up upon the repairing pencil, and the whole work is to be smooth'd either with the same pencil or another something larger; the gold being pressed into the dents, into which it could not be so easily carried by the squirrel's tail.

The work having been thus far gilded, must be set by to dry in order to be either burnished or flatted.

Burnishing is smoothing and polishing it with a burnishing tool, which is usually a dog's or woolf’s tooth or a blood-stone fitted into a handle for that purpose. See BURNISHING.

Flatting it is giving it a light lick, in the places not burnish'd, with a pencil dipt in size, in which a little vermilion sometimes has been mixt. This serves to preserve and prevent its flawing when handled.

The last operation is the applying the vermeil in all the little lines and cavities; and to stop and amend any little faults with shell gold.

The composition call’d vermeil is made of gum guttæ, vermilion, and a little of some ruddy brown colour ground together, with Venetian varnish and oil of turpentine. Some gilders instead of this, make shift with fine lucca or draggon's blood with gum water.

Sometimes instead of burnishing the gold, they burnish the ground or composition laid on the last before it, and only afterwards wash the part over with the size.

This method is chiefly practis'd for the hands, face, and other nudities in relievo; which by this means, don’t appear so very brillant as the parts burnished; though much more so than the parts perfectly flat.

To gild a piece of work, and yet preserve white grounds, they apply a lay of Spanish white, mix'd with a weak fish glue on all the parts of the ground, whereon the yellow or the last lay might run.

The method of GILDING in oil.

This operation requires much less apparatus than that before mentioned.

The basis or matter whereon the gold is laid, in this method is the remains of colours found settled to the bottom of the pots in which painters wash their pencils.

This matter which is very viscid or sticky, is first ground, and then pass'd through a linen cloth; and thus lay'd with a pencil on the matter to be gilt, after it has been wash’d once or twice over with size; and if it be wood with some white paint.

When this is almost dry, but yet is still unctuous enough to catch and retain the gold, the leaf gold is laid on; either whole, if the work be large, or cut to pieces if smaller; the leaves of gold are taken up and laid on with a piece of fine, soft, well carded cotton; or sometimes by a palat for the purpose, or sometimes with the knife with which the leaves were cut, according to the parts of the work that are to be gilded, or the breadth of the gold that is to be laid on.

As the gold is laid on, they pass over it a coarse stiff pencil or brush to make it stick, and as it were incorporate with the ground; and after this they mend any cracks that may have happened in it, either with the same pencil or one that is smaller; as has been shewn before in water Gilding.

This kind of Gilding is chiefly us'd for domes and roofs of churches, courts, banquetting-houses, &c. and for figures of plaister of Paris, lead, &c.

The method of GILDING with liquid gold.

This is perform'd by gold reduc’d to a calx and amalgamated with Mercury, in the proportion of about an ounce of Mercury to a dram of gold.

To perform this, they heat a crucible red hot, and then put the gold and Mercury into it, stirring them gently about till the gold be found melted, and incorporated into a mass with the Mercury.

When this is done, they cast them into water to wash and purify them; and out of that into other waters, where the amalgama which is almost as liquid, as if there were nothing but quicksilver in it, may be preserv'd a long time for use.

Before they proceed to lay this amalgamated gold on the metal, they first render the metal rough, by washing it over with aqua fortis or aqua secunda; and afterwards rinse the metal in fair, water, and scour it a little with fine sand, and then it is ready for the gold.

Then they cover over the metal with the mixture of gold and Mercury, taking it up with a flip of copper or a brush made of brass wire, spreading it as even as possible, to do which they wet the brush from time to time in fair water.

Then they set the metal to the fire upon a grate or in a sort of cage, under which stands a pan of coals; and in proportion as the Mercury evaporating and flying off discovers the places where gold is wanting, they take care to supply them by adding new parcels of amalgama.

Then the work is rubb'd over with the wire-brush dipt in beer or vinegar, which leaves it in a condition to be brought to a colour, which is the last part of the process; and which the gilders keep to themselves as a mighty secret; though it is cer tain, it cannot differ much from the manner of giving gold species - their colour in coining.

The method of GILDING by fire on metal.

There are two ways of performing this. The one with leaf gold and the other with liquid gold.

To prepare the metal for the first, they scratch it well or rake it; then polish it with a polisher; and afterwards set it to the fire to blue, i. e. to heat, till it appear of a blue colour.

When this has been done, they clap on the first lay of leaf gold, rubbing it lightly down with a polisher; and expose it thus to a gentle fire.

They usually only give it three such lays or four at the most, each lay consisting of a single leaf for common works; and of two for extraordinary ones, after each lay it is set fresh to the fire, and after the last lay, the gold is in condition to be burnish’d.

The way of GILDING and LACKERING in oil.

Of mixing and laying on the gold size.

1. First prime the piece with the priming. Take the best gold size, fat oil, of each according to the quantity of your work, grind them well on a stone, and put them into a gally-pot.

2. Pass the piece all over with a clean brush dipt into this size, but do not lay it on thick, jobbing and striking the point of the pencil into the hollow places of the carv'd work, so that no part may escape; for if any place be untouch'd with the gold size, the gold will not stick upon it, and in those places the work will be faulty.

Let it stand by (perhaps twenty four hours or more) so that it may be but just clammy enough to hold the metals, to know if it be in a fit condition; breathe upon it, and if your breath remains upon it like a mist, you may then, lay on your leaf gold; or if it is so dry, that it does not discolour, nor stick to your finger, but is clammy, and not parting very readily with your finger; it is then in a fit temper.

3. If you should lay on your metal before the size is dry enough, it would as it were drown the leaf gold, silver, &c. and deprive it of its gloss and lustre; and if it should be let stand till it is too dry, then the gold, &c. would not stick.

How to lay on leaf gold.

Cut the leaf gold and silver on your Gilding cushion, with a thin, broad, smooth, sharp edg'd knife.

Then having your pencil, cotton or pallat ready (made of a fguirrel's tail) breathe upon the gold, and touch and take it up, and lay it upon the place you intend for it, pressing it down close with your pencil or cotton.

And if any parts have escaped being covered with the gold, cut some small pieces and lay them on; proceeding after this manner, till the whole work is gilded or covered with your metal.

After twenty four hours, jobb down and press over the whole work gently with a fine large brush, to make the gold stick upon all the uneven and hollow parts of the carving; then with fine soft shammy leather, as it were polish and rub it over smoothly.

This being done, the gold will appear of an admirable lustre, and the beauty of it will be so durable, that though it be expos'd to the wind and weather, it will not receive any damage for many years.

GILDING. To lay gold on any thing.
Take red-lead ground fine, temper it with linseed-oil, write with it, and lay leaf gold on it, let it dry and polish it.

To gild GLASS.
Take chalk and red-lead of each a like quantity, grind them together and temper with linseed-oil; lay it on, and when it is almost dry, lay leaf gold on it; let it dry, and then polish it.

To gild IRON with a water.
Take spring water three pounds, roch allum three ounces, Ro man vitriol and orpiment of each one ounce, verdigrease twenty four grains, sal gemma three ounces; boil these all together, and when it begins to boil, put in tartar and bay-salt, of each half an ounce; continue the boiling a good while, then take it from the fire, strike the iron over with it, dry it against the fire, and burnish it.

To GILD IRON or other metals with GOLD.
Take one pound of liquid varnish, linseed-oil and turpentine, of each one ounce; mix them well together, strike them over any metal, and afterwards lay on leaf gold or silver, and when it is dry, polish it.

To GILD silver, bras, or copper with GOLD WATER.
Take two ounces of quicksilver, put it into a crucible, set it on the fire, and when it begins to smoak, put in an angel of fine gold; then take it off immediately, for the gold will be presently dissolv'd: then, if it be toothin, strain a part of the quicksilver from it through a piece of fustian; when you have done this, rub the gold and quicksilver upon bras or silver, and it will cleave to it; then put the said bras, or silver upon quick coals, till it begins to smoke, then take it from the fire, and scratch it with a hair brush; this do till all the Mercury is rubb’d as clean off as may be, and the gold appear of a faint yellow; then heighten the colour with sal armoniack, bole and verdigreas, ground together and tempered with water.
Where you must take notice, that before you gild your metal, you must boil it in tartar or beer and water.

Another water for GILDING iron, steel, knives, swords, &c.
Take fire-stone, reduce it to powder, put it into a strong red wine vinegar in a glaz'd pot for twenty four hours, adding more vinegar to it as it evaporates or boils away; into this water dip the iron, steel, &c. and it will be black; dry it, and then polish it, and you will have a gold colour underneath.

Another way of GILDING IRON.
Take salt-petre, roch allum burnt, of each an ounce, sal armoniack two ounces, all reduc’d to fine powder; boil them in strong vinegar in a copper-vessel, with which wet the iron, &c. and then lay on leaf gold.

Another way.
Grind roch allum with the urine of a boy, till it is well dissolv’d, with which anoint the iron, heat it red hot in a fire of wood coals, and it will be like gold.

Another way.
Put two ounces of allum, three ounces of sal gemmae, Roman vitriol and orpiment, of each one ounce, of fos aeris twenty four grains into three pounds of water; and boil them all in tartar and water, as is directed in Gilding iron with water.

To make iron of a golden colour.
Take linseed oil six ounces, tartar four ounces, aloes an ounce, saffron ten grains, turmerick four grains; yolks of eggs boil'd hard and beaten four ounces, boil them all in an earthen vessel, and anoint the iron with the oil, and it will look like gold. If the linseed-oil be not enough, you may put in more.

Another way for iron, glass or bones.
Take a new lay’d egg, make a hole at one end, and take out the white and fill up the egg with quicksilver two parts, sal armoniack reduc’d to a fine powder one part; mix them all together with a wire or little stick, stop the hole with melted wax, over which put an half egg-shell; digest it in horse dung for a month, and it will be a fine golden coloured liquor.

Take bole armoniack and oil of ben, of each a sufficient quantity; beat and grind them together, and smear the wood, or stone, and when it is almost dry, lay of leaf gold, let it dry, and polish it.

To gild with leaf gold.
Grind leaves of gold in a few drops of honey, and add to it a little gum water, and it will be excellent to write or paint with.

To gild silk and linen.
Lay some parchment glue on the silk of linen, gently that it may not sink; then mix and grind ceruss; and verdegrease together, of each a like quantity, mix them with varnish in a glaz'd vessel, let it simper over a small fire, and keep it for use.

Another of a pure gold colour.
Take the juice of fresh saffron, or saffron ground, the best clear orpiment, of each a like quantity; grind them with goat's gall or gall of a pike (which is better) digest twenty eight days in horse-dung, and it is done.

To gild iron or steel.
Take of tartar one ounce, vermilion three ounces, bole armoniack and aqua vitæ, of each two ounces, grind them together with linseed-oil, and put to it thefo of a hazle-nut of lapis calaminaris, and in the end grind a few drops of varnish; then take it off the stone and strain it through a linen cloth (for it must be as thick as honey) then strike it over iron or steel, let it dry; then lay on your silver or gold and burnish it.

To colour tin or copper of a gold colour.
Set linseed-oil on the fire, scum it and put in amber, aloes, hepatick, of each a like quantity, stir them well together till it grows thick; then take it off, cover it close, and set it in the earth for three days; and when you use it strike the metal all over with it, let it dry, and it will be of a golden colour.

To silver any metal.
Dissolve fine silver in strong aqua fortis, and put in as much tartar finely powdered as will make it into a paste; with which rub any metal, and it will look like fine silver.

To gild so as it shall rot out with any water.
Take calcin'd oker and pumice-stone, of each like quantities, and a little tartar, beat them with linseed-oil and five or fix drops of varnish; strain all through a linen cloth, and with this liquor you may imitate Gilding.

To gild paper.
Grind bole armoniack with rain water, and give one laying of it when it is dry, take glair of eggs, and add to it a little sugar candy and gum water, which lay over the former, and upon this, when it is dry enough, lay leaf silver or leaf gold.

To gild the leaves of books.
Take bole armoniack eight penny weight, sugar candy two penny weight, mix and grind them with glair of eggs, then on a bound book (while it is in the press, after it hath been smear'd with glair of eggs and is dry'd) smear the said composition, let it dry, then rub it well and polish it; then with fair water wet the edges of the book, and suddenly lay on the gold, press it down gently with cotton, let it dry, and then polish it with a tooth.

Of GILDING wood with burnisht gold and silver.

1. Take parchment size, for priming or whiting the piece, do it over with this seven or eight times, letting it dry between every time.

2. If it is a carv'd frame, that is to be gilded, grind yellow cker fine with water, adding to it a little weak size to bind it; warm it and colour over the frame, and let it stand to dry.

3. Take either of the gold sizes. (See SIZE) but rather the seventh, melt it and make it blood-warm; but so as it may be somewhat thin, stir it well with a fine brush, and size the piece over twice with it, without touching the hollows, or deepest parts of the carving; because the yellow colour first laid on, is near in colour to the gold, and a fault in the gold's not taking, will not be so easily cover'd because of the shadows.

4. Let it stand five or six hours to dry, and try if your gold will burnish upon it, if not alter your gold size, and do it over again.

5. To lay on the gold for burnishing, do as follows.
Having fixt your work almost upright, but in a posture a little reclining that the water may run off, and not settle in any of the cavities; lay some leaves of gold on your Gilding cushion, which hold in your left-hand with your pallat and pencil; let also a bason of water stand by you, and dry whiting to rub your knife sometimes with, that the gold may not stick to it.

6. Then with a swan's quill pencil, or a large one of camer's hair, being dipt into the bason of water, wet so much of your work as will take up three or four leaves, beginning at the lower part, ascending and Gilding upwards, laying on either whole leaves or half leaves, or lesser pieces as the work requires, taking care to make as little waste of gold as possible.

7. When you have laid on the gold all over what you first wetted, then wet another part of the work, and lay on the leaves of gold with your pencil, cotton or pallat, pressing them down close; following this method, till you have finish'd the whole piece.

8. Having done this, look over your work examining if any parts have escap'd Gilding, and if there is any such cut some leaves of gold into small pieces, and wetting the ungilded parts with a small pencil, apply the bits of leaf gold to them, then set the work by for twenty four hours; but no longer, and then begin to burnish it.

9. The burnishing is to be perform'd with a tool call’d a burnisher, by rubbing it smoothly on it, till it attains a gloss; and having burnish’d so much of the work as you defign, leave the round of the carving untouch'd, and some other parts which you shall think fit; which being rough, if compar'd with the other, will set off and beautify that which is burnish’d.

10. Those parts which are not burnished, must be clothed or secur'd with size, seed lac, varnish or lacker, if you would have it to be deep coloured; but you must take care to touch these parts only, and not that which has been burnish’d.

11. Then the work is to be set off with lacker varnish, mixt with sanguis draconis and saffron or with ornatto, with which and a fine pencil touch the hollowness of the carving, hollow veins of leaves and foldings; and if you do not think it deep enough, go over it again, with the lacker before directed.

12. To lay on silver size.
Take silver size newly ground, and mix’d with weak size, warm it, and a clear pencil fit for the work, size it over once or twice, then let it stand to dry to a just temper, trying it whether it will burnish, which if it will, burnish it, but if not, you must size it again with some alteration in the size.

13. Then wet the work, and lay on the leaf silver, after the same manner directed for the laying on of leaf gold, and when it has been so done, burnish it over, if it be not frosty weather; but if it be a hard frosty season the priming will be apt to peel off, and the size will be apt to freeze in laying on.

14. Let your parchment size be something strong and new; for if stale, it loses its strength; nor should you grind any more gold or silver size, then what you will want for present use.

And be sure to keep your work clean and free from dust both before and after it is gold siz’d and gilded; otherwise in Gilding it will be full of scratches, and look ill.

The method of GILDING metals.

In order to prepare the gold for this work. Take leaf gold, or ducket gold beaten very thin, and cut into little bits, what quantity you please, put it into a gally-pot, and put to it so much - quicksilver, as will just cover it; stir them with a stick and make an amalgama, and when you have so done, strain them through a piece of shammy leather, squeezing the leather hard with your hand; that which remains behind in the leather, and looks like silver, is the gold amalgamated, and that which is to be us'd in this work.

The method of Gilding silver, or brass, copper, or prince's metal.

1. The thing to be gilded must first be scrubb'd with a wire brush and a little fair water, till it is perfectly clean.

2. Then having put an ounce of quicksilver into a vial, drop into it three, four or five drops of aqua fortis; with this mixture and a rag rub over the metal to be gilded, till it is every whereas white as silver.

3. Then with a small knife spread your amalgamated gold over the whole piece, taking care not to miss any part of it; then give it a heat over a fire to force the quicksilver to evaporate or fly away, and the gold will remain sticking close to the piece.

4. But before you give it a thorough heat, let it have two or three little heats, that you may with a small hair brush, almost like that of a comb, dab and spread the gold, which you may the easier do, because the warmth you give it makes the quicksilver the more ready to spread; after which give it the thorough heat beforementioned.

5. Afterwards take it from the fire, and with a hair scrub brush, which has never touch'd quicksilver, rub and cleanse it as you did before. And you must take notice, if there be any spot left ungilded, you must after you have cleans'd it with the wire brush, proceed again as before.

6. If you would have the work more rich and lasting, besmear it again with quick/over and aqua fortis, and lay on the gold again, after the same manner as before; and this you may repeat so often till the gold lies as thick as your nail upon the metal you gild.

7. To heighten the colour if you think fit.
Take argal, salt, and sulphur of each what quantity you think convenient, and put to them as much fair water as will just cover the thing that you put into it to be gilded; boil them over the fire, and having ty'd the gilded piece to a string, put it into the boiling liquor for a little space, viewing it every minute; and when it has obtain’d a colour according to your mind, put it immediately into cold water, and it is done.

Another way to heighten the colour of gold.
Take nitre, sal-armoniack, sandever, verdigrease, white and green vitriol of each a like quantity, grind them with white wine vinegar, which lay over all your work; then lay it on a fire, and give it a small heat, that it may smoak, and so take it off and quench it in urine.

Another way to gild silver, brass, &c.
First cleanse the metal with aqua fortis, then quicken your work with Mercury, then take off the gold amalgamated as before directed, and lay it on with a small knife, spreading it every where, and do in all things as before directed.

To silver over bras or copper plates, as clock-makers do their dial-plates.
Procure either leaf or burnt silver, and put to it as much aqua fortis as will cover it, let it stand an hour or two; then decant off the aqua fortis as clean as may be, wash the silver three or four times in fair water; and then let it dry, and then mix with it, one part of fine argal to three parts of the silver, with a little fair water.
When you use this, rub it on the work with a cork, till it is silvered all over, and lies very fair, and afterwards dry it well with a linen cloth, and warm it; then wash it over three or four times with the best white varnis), which will preserve it from tarnishing, and other injuries of the weather.

To gild brass, cooper, iron or sleel, with leaf silver or gold.
If you would gild brass or old iron, first cleanse it very well with a wire brush; but if it is new iron or steel, first make it very smooth, and hatch it all over very neatly with a hatching knife (which is a knife with a short blade and a long handle).
Then give it an heat on a charcoal fire, so as to make it look blue, take it from the fire and lay on the gold or silver, and burnish it down a little with a blood-store or burnisher; and then give it the same heat again, and burnish it all over.
This work of Gilding may be repeated six, eight, or ten times, still observing to give it the same heat, before you lay on the gold and silver, and then burnish it as before directed.

Beat in a mortar and grind together bole-armoniac and oil of behn, of each a sufficient quantity, with this smear the wood or stone, and when it is almost dry, lay on the leaf gold; let it dry and polish it.

To GILD with leaf GOLD.
Grind leaves of gold with a few drops of honey, to which add a little gum water, and it will be excellent to write or paint with.

To GILD so as it shall not rot out with any water.
Take calcin’d oker and pumice-some of each alike quantity and a little tartar, pound them with linseed-oil and five or fix drops of varnish, strain all through a linen cloth, and with this liquor you may imitate Gilding.

Grind bole-armoniack with rain water, and give one laying of it; being dry, take glair of eggs, and add to it a little sugar: candy and gum-water, which lay over the former, and upon this (when it is in a fit dryness) lay on either leaf silver or gold.

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