Technical experiments 2: Creating the foil pattern

Tools:

As I already described in my first article I purposed to produce the waffled structure by impressing intersecting lines. I was inspired by a special technique used in leather working to create decorative lines with a tool called creaser. But for the fine foil pattern a common modern creaser was too rough. After some experiments with a blunted knife edge I modified two riffle files whose working surface was v-shaped in cross-section. I ground off the cut and polished the lower edges.

Fig.1: Riffle files with polished working edges: a: “knife-shaped face, b: diagonal square-shaped face

 Foil Materials:

1. 935/000 silver sheet, material thickness: 0,03mm (See my article: “Producing a piece of silver foil”)

2. tin foil, material thickness: 0,03mm

Work surface material:

The third relevant component was the surface on which the foil has been worked. It had to be flexible, so the foil could be deformed. I did some preliminary tests on small boards of pine and beech wood and on deformable pitch, usually used for repoussé work. Because of its structure pine wood proved to be unsuitable. The beech wood and the pitch were both too hard. Finally I found two better materials which were much more appropriate:

1. beeswax

2. sheet of lead (1mm)

The foil has to be fixed on the working surface. That was no problem in case of the beeswax, which has itself enough adhesive power to hold the foil in place. On the lead I fixed the foil with the help of adhesive tape. A more authentic way could be the use of an organic adhesive like hide glue or a mechanical attachment.

Impressing the pattern:

The first step was to form parallel lines by running the tool along a ruler by a forward movement. Then the same action was repeated after turning the work piece by 90 degrees.

Fig. 2: Tracing the lines

 

The result was a waffle pattern! However it could have been more regular. But perhaps with some more practice it could be improved.

Fig. 3 a+b: work piece, tin foil on beeswax, knife-shaped tool, backside

Fig. 4 a+b: work piece, tin foil on beeswax, knife-shaped tool, frontside

 

The tin foil proved to be too soft. There was no increasing of hardness after the deformation, so the pattern could be crushed easily.

The silver foil was a little bit rigid even after repeated annealing. But against my expectations it could be well processed on both work surfaces.

Sometimes I traced the lines twice or I started with the knife-shaped tool and retraced the lines with the diagonal-square-shaped one.

There are remarkable parallels in irregularities between my work pieces and original foils:

Fig. 5a: workpiece, silver foil on lead, knife-shaped tool, retraced with diagonal-shaped tool
Fig. 5b: disc brooch, Rödingen LVR Landesmuseum Bonn 56.445, 0-2
Fig. 6a: workpiece, silver foil on lead, knife-shaped tool
Fig. 6b: disc broch, St. Severin, Römisch-Germanisches Museum Köln 50.287
Fig. 7a: workpiece, tin foil on beeswax, blunted knife edge
Fig. 7b: disc brooch, Monsheim Römisch-Germanisches Zentralmuseum O.15370

 

It is definitely possible to produce a more or less regular waffle pattern in the way described above. Probably the result could be improved if a double edge creaser is used, that makes it easier to form regular parallel lines.

But more experiments with different materials are necessary to allow significant comparisons with the original foils. It would also be interesting to see if boxed waffle or ring-and-dot pattern could also be made in that way.


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