In RX Labs,  in order to make it easy for optometry practitioners to read the invisible marks on the lens, RX lens are normally inked with waterproof image, known as the “Yellow Label” image and currently attained by pad printing or inking digital printing in the industry.

Pad printing is to transfer cliche pattern to the lens surface. Its advantage is its simplicity and fast speed in producing excellent quality images, but the big downside is that cliche plates have to be prepared for each image. Just like ink printers, digital ink printing system allows you to print any image without cliche need at anytime, which is why digital inking system is replacing pad printing. But compared to pad printing, digital ink system has longer cycle time and needs to be well maintained, otherwise nozzles will be blocked easily. At present, digital inking printing system can be sorted into two classes according to different ink used. One is solvent ink, the other is UV ink. UV ink point can be easily controlled to get precise and fine results, thus it can produce image with finer and better quality compared to wax solvent ink.