Gold Leaf
Also: Gold Sheet, Leaf Metal (Gold)
Gold hammered or rolled into ultra-thin sheets, used in gilding, arts and crafts and food processing.
Gold leaf is produced by mechanical rolling or the traditional craft of gold beating: a gold bar is first rolled mechanically into a fine strip, then placed between layers of parchment or plastic film and beaten with thousands of hammer blows until it forms ultra-thin sheets. The result is foil with a typical thickness of 0.07 to 0.15 micrometres — thinner than a human skin cell. This is made possible by the extraordinary ductility of gold: of all metals, it can be hammered and drawn the furthest without tearing.
Fineness and grades
Commercial gold leaf is available in various karat grades:
| Designation | Karat | Fineness | Colour note |
|---|---|---|---|
| True gold (transfer) | 23–24 kt | 958–999 ‰ | Deep yellow |
| Ducat gold | 23.5 kt | ~979 ‰ | Warm yellow |
| 22-karat | 22 kt | 916 ‰ | Slightly greenish |
| White gold leaf | 12–18 kt | 500–750 ‰ | Silvery-white |
For food use (confectionery, chocolates, beverages), only gold leaf with food additive status E 175 is permitted — at least 22 karat (916 ‰), free of nickel and lead. The current gold price directly influences material costs, since even a few grams yield a considerable area.
Production: gold beating
The traditional craft of gold beating is structured in three phases:
- Pre-rolling — the bar is mechanically rolled to a strip thickness of approx. 0.1 mm.
- Cutching — strip pieces are placed between skins (cat gut, ox intestine) and beaten by hand or machine to an intermediate thickness.
- Finishing — in a second pack, the sheets are brought to their final thickness and cut to the format 80 × 80 mm.
Area yield (approximation):
1 g Au × (1 / density 19.32 g/cm³) × (1 / thickness 0.00001 cm) ≈ 0.5 m²
(thickness 0.00001 cm = 0.1 µm, typical hand-beaten product)
Applications
- Gilding of picture frames, sculptures, church furnishings and architectural details
- Lettering and bookbinding gilding (bookbinding, signs, glass gilding)
- Culinary — E 175 on chocolates, in digestifs and on desserts
- Medicine / cosmetics — facial masks, occasionally wound dressings (antimicrobial effect of low gold concentration)
- Electronics — ultra-thin contact coatings in specialist applications
A direct material value can be calculated at any time using the gold calculator or the melt value calculator — relevant, for instance, when purchasing gilded objects whose gold content is minimal.
Distinction: real gold vs. imitation
"Schlagmetall" or imitation gold leaf made from brass or copper-zinc alloys looks similar but tarnishes and is considerably cheaper. The distinction is made by the fineness hallmark, or for loose sheets by the acid test or a gold testing device.
Key takeaway
Gold leaf combines thousands of years of craft tradition with modern industrial applications. The decisive factors for quality and price are fineness and thickness — both determine whether a sheet is suited to fine gilding, food use or technical purposes.