There’s a certain aesthetic I associate with older labels, signs, and equipment control panels. They have two contrasting colors and a three dimensional feel. It has mostly faded away by now, replaced by crisp flat printing with multiple solid colors or even full color halftone. I hadn’t thought much about those old panels until I had the opportunity to look over some dusty retired equipment for making them.
This particular material was “Gravoply” and it is still available for order. We can specify from a wide selection of colors, though the core (rear) color selection is a little more limited than selection for surface (front) color. The dimensional feel is a function of how they are used to create signage: a rotary engraving tool cuts away the surface layer and expose the core layer to produce a display with two contrasting colors.
This rotary tool was held in a pantograph to trace templates on Gravoply. Laying out a particular design meant working with individual letter templates in a simplified version of how past typesetters did their jobs. While in concept a pantograph could allow arbitrary scaling, it appears scaling is limited in this particular implementation. Otherwise there wouldn’t need to be multiple sizes of letter templates.
This technique is unforgiving of mistakes. If the rotary tool went off track, it would cut portions of surface material that was not intended to be cut away. When this happens, the user has no choice but to start over. Which was the explanation for why these pieces haven’t been used in years: they moved away from this system as soon as a cost effective and less frustrating alternative was available.
Visiting the web site of Gravograph today, I see their products on the front page are computer motion controlled machines,. Though they still make pantographs for doing things the old fashioned way, materials for mechanical removal like Gravoply are typically cut with small CNC vertical mills. Plus they also have material designed for engraving by laser. Technology has moved on, and the company behind Gravoply has evolved with it.
I found the pantograph an interesting mechanism and I might ask to use it in the future for the sake of getting some hands on time with a mechanical anachronism. But I’m not likely to actually create something significant using a pantograph, at least not as long as I have a CNC engraver at my disposal.