

Wednesday, September 30, 2009

Printing Plates 101

I've gotten this question a couple of times since I posted my Chipper Press Plate, so I'm going to go ahead and answer it.

I haven't actually seen any of them in person, but wouldn't it make sense that the plate would be reversed?

How do these things work?
- Mark's Ephemera
It seems intuitive that image on the plates should be backwards, right? We've all seen filmstrips in school about the wonders of Gutenberg and his movable type, and made potato art and used rubber stamps before. The writing and pictures on those things are all reversed, so wouldn't the press plates be reversed too? Only if the plate ever actually touched the card like those other devices do when they print. In most modern printing operations that's not the case. So, Mark (and Tunguska), here's how they work.

Most commercial printers nowadays use a technique called offset printing. Instead of the printing plate directly applying the ink to the paper, the plate transfers the ink to a rubber cylinder which in turn applies the ink to the paper. So instead of pressing the plate down on the paper to print the card, three cylinders roll along to do the printing. One cylinder has the print plates, one transfers the ink to the paper and a third pushes along the paper through the press. This method is the cheapest way to produce a large number of high quality images. The plate doesn't wear out as fast because it's not coming in contact with the paper and the rubber cylinder makes better contact with the paper than a metal cylinder ever would.

So why is the press plate not reversed? Well, it's true that when transferring the ink to the paper the image has to be reversed so it prints properly, but the image is reversed when the plate transfers the ink to the offset cylinder. If the image was reversed on the press plate it would he correct on the offset cylinder (I've misspelled cylinder 48 times while writing this post) and when the ink transferred to the paper it would be reversed again. This page has a semi-decent picture (well, for a Bigfoot sighting) of a plate in action. So know you know why those press plates don't have reversed images. Now, you would be perfectly reasonable in asking why the press plate you pulled out of that pack is flat instead of round, but I don't know so ask someone else. Not Thorzul either, because he's got his own Press Plate Puzzler he's chewing on.

Ok, since you slogged your way through my 3rd grade science report of the offset printing press the readers who made it this far get a treat:


Calm down folks, you ain't seen nothin' yet! Just be careful and don't look at the image straight on or its glory will melt your face like the Nazis who looked at the Ark in Indiana Jones - don't say I didn't warn ya...

Awww yeah. Yellow press plate of the back of a Minnesota Twins relievers Topps Total card. Now you know why I keep screaming for Total to come back. However, if there is a JC Romero super collector out there who is desperate for this thing I will trade it... but only for any other press plate card in existence. Seriously, any of them. You don't even have to tell me what it is, just send something and it's yours. You might even get away with passing off a Leaf Steel card with the sides filed down. Please?


Mark's Ephemera said...

Thanks for the lesson, Perfesser dayf.

Tunguska said...

Agreed, thanks for the explaination. Now the world makes sense again!!!

Seeing as you are on a roll, care to explain why when I am sitting in an empty movie theatre the next person who comes in inevitably ALWAYS sits in the chair directly in front of me??

dayf said...

Tunguska: 'Cuz they're jerks

lonestarr said...

Oh he's good.

lauragray said...

Wow! This is really great! But I am looking for best printing, but i cannot find it. There are so many printing swarming over the net but it is difficult to select the best and i don’t know where to go.

Anonymous said...

Makes sense, but then why are the magenta and cyan printing plates of 2010 Bowman Bo Greenwell different? One is reversed and the other is not? You can check them on eBay right now, one sold and the other is active (as of 5/20/10).

Anonymous said...

Nevermind, figured it out. The regular bowman is offset printing, the chrome is regular.