Pad printing is a printing process used to transfer a 2-D image from the cliche via a silicon pad on to a 3-D object. The unique property of silicon enables it to transfer the image on any type of surface like cylindrical, flat, spherical or irregular. Due to this property this technology is used maximum to print on otherwise difficult to print products. It is widely used in medical industry, electronics industry, computer keys, golf balls, hockey pucks, toy industry, and many others. We have categorized pad printing into three categories depending upon the mechanism used in each.