Dimensional letters are any elements of signage, which have a third dimension — depth, which ranges from just a few millimeters to twenty or more centimeters. For example channel letters can also be described as dimensional letters but with a built-in lighting. The range of depth may vary widely, and therefore there are numerous methods and materials for manufacturing of dimensional letters. We will expand on those, which are worth mentioning.
Let’s begin with the thinnest and simplest letters which are cut from PVC – polyvinyl chloride. Their depth depends on the material that can be 2mm / 3mm / 5mm / 8mm / 10mm / 19 mm thick. Material itself is white, thus in order to get a different colour, the front side is covered with a film and the edge is painted. This is one of the least expensive methods of dimensional letters’ manufacturing.
We are using a 3mm thick Perspex, due to the fact that coloured Perspex that is thicker than 3 mm is rarely available in stock (this means that it has to be ordered first, which in turn extends projects duration to unacceptable level). These types of letters stand out due to their presentability, since the specular highlights make them look more expensive and properly. To make the letters look bulkier, it is recommended to leave a space of at least 5 – 10 mm between the letters and the wall.
Letters made of transparent Perspex (e.g. 10-20 mm), make a machine-cut sign board look somewhat weightless. To change the color, the front panel could be covered with an additional layer of coloured Perspex, polished stainless steel or coloured film. But it has to be borne in mind that after installation (using glue or screws), the fixtures at the edge of the sign board will be visible, and in some cases this will impair the exterior view.
Usually we use MDF for letters which are thicker than 22 mm. Having cut the letter from the plate, we then cover it with a special paint, which makes it compare more favourably with a PVC letter. However the sheer complexity of this job increases the cost of the letter.
Foam plastic letters is the cheapest and simplest way of manufacturing 50mm thick, 100mm thick or even thicker dimensional letters. Having cut the letter, we cover the foam plastic with special paint for outdoor use, which makes the letter extremely weatherproof. A substantial number foam signage that we produced is installed outdoors.
To manufacture small letters (with dimensions within 550x1100mm plate) we use a special XPS foam plastic, which lacks a ball / grain-type structure typical for foam plastic. Letters from this material could be up to 95mm thick. If there is a need for a larger letter, we would use an ordinary white foam plastic, usually the one with the highest density (EPS200).
Bonded letter is a PVC or Perspex letter with a sidewall glued to its edge. The width of the sidewall determines the depth of the letter. After bonding together, the letters are covered with coloured films. In fact a sidewall of the letter and its front side can have several different colours. As a matter of fact, if we install lighting inside the letter, we will get an illuminated letter.
During our practice we have never manufactured big channel letters without any lighting inside… Nevertheless it is possible… if we take a letter, which was manufactured using a technique described in chapter Channel letters, and take out all electrical stuff, the volume will be the only benefit of this letter. But what a bargain!