Man this could open a can of worms with different variations for replies...
IMO:
Patch = Piece of GU that comes from ANY part of Jersey that is NOT the main material of Jersey.... (Trims/hems, Numbering, Lettering, Logos, Tags, etc).
Printing Plate = Piece of aluminium that is used to print the cards. They're becoming more and more popular (if that's the right word). - these are much the same as Newspaper plates they print the papers with, only smaller. There are 4 different colours (Black, Magenta, Cyan, and Yellow).
1/1 = Card printed "1/1", "1 of 1", "1 of a kind", or another form of card (Letterman) that might be numbered otherwise (Harris' Letterman's are #/6 one for each letter, but technically, there's only ONE of each CARD).
And one of my beefs...
Colouring of Patch/GU cards = Most people generally call 1 colour the same colour. But others some how call the same colour a different one.
Check my sig, the card on the right is a 3 Colour Patch (White, Navy & Silver). However, there's 2 sections that are Silver, and I think there is another white section. Some people would call this a 5 Colour Patch - NOT ACCURATE.