Illuminated led sign board back-lit sign are widely used for advertising industry. The led letters sign and logos front part made by metallic stainless steel, or aluminum, depth more than 2 cm, backside is made by import translucent acrylics, inside with led lights installed. Front part metal finish could be proceed with gold mirror, gold brush, silver mirror, silver brush, black mirror, black brush, rose gold mirror, rose gold brush, bronze, copper, or any painted colors according to Pantone code. Back side are mostly used translucent acrylic which is high light transmittance, in some circumstances, they could be done with red, blue, orange, green color as well under request. Led lights are chosen based on the sign working area, there are led lights specially used for indoor and outdoor, It is very important to choose led lights which decide how long time use it and frequency of maintenance.