I printed promotional products for many years... using both the screen technique and pad... contents of the inkwell have a lot to do with how long a print will hold up... as in the ratio of ink... hardner... and the amount of thinner used...
most of the prints I'm familar with are no bigger than the inside of your palm... tee shirts and such I haven't any experience with...
with pad printing metal plates are used... an image is burned into the plate and then placed in an inkwell... a blade pulls ink over the plate then another sharper blade pulls the ink away... a pad then comes down and strikes the plate picking up ink ready to transfer to the product... this all happens in a few seconds... pad pressure determines how distorted the image outcome will be...
screen printing involves a cheesecloth type material with the image burned directly into the screen... ink is poured directly into the screen area and using what is called a squeegee the ink is applied directly to the product... depending on the amount of pressure used while applying determines the coverage or thickness of the ink prints...
both processes are much tougher to master than one might think... there is so much that goes into the preparation process that it is just to hard to explain without seeing it...