(stone) Re: water gilding

["dondougan@zzzzzzzz" <dondougan@zzzzzzzz>]

Norm,

What I have always found to be the important working qualities about the bole is not so much how smooth it is, but rather that is extremely fine, dense, and soft enough that light pressure can be applied and effect the desired change.

The oil-sized stone is a whole different critter.
Though the viscosity of the oil size will be such that there is some self-leveling, there are usually traces of the brush strokes from the application.
Even assuming the stone is perfectly smooth from your chisel (often each stroke of the hammer/mallet will transmit small choppy little ridges to the stone surface), or even if the area to be gilded has been sanded smooth to 1200 grit the stone is hard and unyielding.
Those two facts, coupled with the relative thinness of both the oil size layer and the leaf layer, make it impossible for our touch to be light enough to burnish the metal surface without crushing or scratching through to the stone.

I have not found the water-gilded surfaces to be any more durable than oil gilded in terms of scratching, though possibly to some extent in direct impact cases because the softer bole/gesso/wood substrate is soft enough to absorb some of the blow, while on stone the resistance of the substrate forces the full impact of the blow to affect the softest material (the gold and the layer of size).

BTW - If you don't like the way oil size works, don't ever even try the acrylic polymer types . . . they dry soft and rubbery under the leaf, and are even worse to damage.

I try to use the gold (or other types of metal leafing too) for the quality it provides as applied.  The contrast between the shine of the metal and the honed stone (I almost never polish the stone that has leaf applied to it, but leave it honed to perhaps 400 grit if smooth, or left with the natural cleft surface if slate) provides plenty of drama.

The times when I really want the polish of the gold to show up I am usually not using stone at all - usually the substrate is wood or cast paper into which the rough form is worked, then multiple layers of gesso (real made-from-scratch rabbit-skin glue and whiting gesso - not acrylic gesso as is used for painting on canvas) are applied and the surface is carved and/or sanded to shape.  That is followed by the coat of bole (whichever color is most appropriate red bole gives a very warm appearance, yellow bole or gray bole might be used if I want a more metallic feel), and then the gold leaf is applied.  After 24 hours to allow the gesso and bole to dry from the leafing operation, I will come in with the agate burnishers.  When burnishing, I try to hit the highlights and don't worry about the nooks and crannies - this actually makes the highlights look shinier in contrast with the duller un-burnished areas of gold.  Then, if I want more overall contrast, I will mount this image
  or form on a piece of dark stone which makes the metallic nature stronger by contrast to the stone or marble.

Good Leafing to You,
Don

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