Making a mould and templates from a poster

A quick, efficient and accurate way of cutting durable templates using one of The Strad’s publications

Makers reveal their special techniques

When I make a copy or model of a classical instrument, I usually take inspiration from The Strad ’s posters. I examine fine instruments in person as often as I can; this way I gather essential sculptural information needed to make a three-dimensional object from a two-dimensional set of plans, such as a poster or a book. In this article I explain how I use a laminated poster by The Strad to make a mould and templates of the archings, f-holes and scroll. I will also illustrate a novel way of using a two-dimensional f-hole template to draw an f-hole on to a three-dimensional arched violin with good results. The poster I am using here is of the 1649 ‘Alard’ violin by Nicolò Amati, published in 1992; it has exceptional photographs. It also has very useful information, albeit limited compared to more recent posters of other instruments.

Stiffening the poster paper

1 First, I glue paper or thicker card stock on to the areas of the poster back, such as the archings and the scroll, that are to be used repeatedly as working templates. A glue paste stick works well for this. It’s good to have two posters to cut up, one for templates and one to keep intact for reference.

I visit a self-help print shop where, using an industrial laminating machine, I can laminate the poster in sections. Their machines use 5mm-thickness pouches which add stiffness and durability to the templates. Before laminating them it is necessary to label each template. Trying to label them afterwards is harder, as the ink tends to rub off the plastic laminate.

The photo shows the poster against a bright window, to help me register the card stock behind the scroll for gluing. Some tape hinges help register the backing.

Labelling the arching patterns

ALL PHOTOS LAURA CHESSIN

2 I label the bass and treble sides, and mark a line up from the edges of the plates for later reference. As you see from the chain of finished arching templates, the edges are cut away. A centre-line mark is also needed, since I cut the patterns in half.

Laying out block mortises

3 Before laminating the images I lay out the locations of the corner and bottom-block mortises. I am referencing another of The Strad ’s posters (the 1735 ‘Baron Knoop’ Bergonzi) with CT scans of a rib garland to help me locate my corner-block locations. The lines drawn here will be cut through the laminate to make the block templates, and will also mark the cut-outs on the wooden mould.

Labelling the corner templates

4 By placing the poster up to a backlight (I use a window with natural light), I am able to see my future corner and end-block layouts clearly, and can label them before the image is laminated. When everything is labelled and laminated, the next step is to glue the image of the front on to a piece of birch plywood, half an inch thick. The glue stick works well here; it will release the image after I have cut out the mould.

Cutting out the mould

5 Once the image is glued to the plywood, I cut out the corner and end-block templates with a sharp knife. Then I saw the mould out with my bandsaw. I’m using the outside black line of the purfling as a guide to define the outline of my mould.

Cutting the f-hole templates

6 I backed up the f-hole areas of the poster with card stock before laminating, so that the f-hole templates stay flat and hard enough to be easily trimmed with a knife or file. I have used templates like this for years and they hold up very well. I have found pressure-sensitive laminates to be softer, less durable and more difficult to trim to shape. The industrial laminating machine that uses 5mm pouches is great!

Drawing the f-holes on the plate

7 Most images of f-holes are taken from the front, which look great until you try bending the template across a voluptuous violin belly. Then they start to look strange. A good way to reduce the distortion is to keep the template flat and allow a light to cast a shadow on to the belly. I use a small LED spotlight mounted about eight feet above my bench, which casts a good sharp shadow, and I use a stack of magnets to raise the template high enough over the belly for me to get a pencil underneath. The further the distance the better; there will be less shift in the size of the shadow. Also, the closer the template is to the belly the better. The shadow enlarges as the template gets further from the belly (using a taller stack of magnets).

The partially carved belly shown here is hollowed out a little, and allows the small magnets on the underside to engage the magnets that are holding the template in place. I start my f-hole layout by marking where the eyes of the ‘f’ belong, and then align the cast shadow accordingly.

The neck template

8 I overlay this part of the poster with white paper to draw my shop neck pattern adjacent to the scroll image, thereby creating a whole new neck template. Earlier I backed the poster image with card stock, so once it is laminated it will be more durable. Even better is to use 1mm-thick maple rib stock for the neck/ scroll template. However, I would not put that through a laminating machine. I would laminate the image, then glue it to the maple stock.

The resulting templates

9 Here are the resulting templates. The Strad’s more recent posters offer more data with modern high-resolution images using CT scans of long and cross-archings, front and back, rib garlands, thickness contours and elevation contours. They are a real treasure trove of information for violin makers.