What is a back tray?
A back tray is a material placed in the back of a 3D built up letter.
What does it do?
Back trays do many jobs in different applications, they are generally as follows:
1. One of the main uses is to diffuse light for LED’s inside built up letters, when back halo illuminating this technique avoids spotting when illuminating on to semi-gloss or gloss surfaces or when the returns are quite small and the light does not have time to diffuse. The most common material is 5mm opal acrylic, some customers prefer frosted acrylic or even clear acrylic with coloured translucent vinyl applied to get different effects.
2. 10mm foam back trays are used as a base to mount LED’s to for face or side/face illumination on built up acrylic or face illumination on built up rim and returns.
3. Some back trays are made from stainless steel or aluminium to help strengthen the letters if the letters are large or mounted onto a bar system.
4. Polycarbonate back trays are used also for strength when the back tray is taking all the weight of big letters but when you need to back halo light in these circumstances this will be the material of choice.