Offset lithography is ancient, but certainly not outdated. While digital printing revolutionized the industry, traditional offset printing maintained its place among, and even chalked up a few distinct advantages over modern digital processes. Offset printing’s staying power leads many to the question, “Which is better for my project? (Offset vs. Digital Offset)”
Offset Printing: How It Works
Offset printing is the most common technique used for commercial (high volume) printing. In offset printing, images are transferred from negatives to aluminum plates through a chemical reaction initiated by the passing of light (like in a photo lab). Each color (CMYK) has its own plate.
Ink and water rollers then douse the plates, and that’s where the lithographic process happens. Ink (which is oil) and water don’t mix, so the flat image maintains ink while the non-printing area collects water (thus keeping ink off of it). The image received by the plates is then transferred to a rubber blanket, and then finally from the rubber blanket to the final surface, often called the substrate.
The original image never touches the paper; the rubber blanket transfers it, hence the term “offset.”
Digital Offset Printing: How It Differs
The main difference between offset and digital offset printing is a little easier to understand. Basically, digital eliminates a good portion of the labor and materials involved in plain old offset. Films, color proofs, plates, having to assemble the pieces – all out the window with digital offset printing. The image is transferred digitally rather than manually.
Offset and digital offset printing are both incredible processes that we’ll be discussing separately in future posts.
Offset Printing Advantages
Let’s go back to old school offset and talk about why it’s still around.
The best thing about offset printing is that your unit cost goes down as your quantity goes up. Once you have your plates and proofs, a great deal of the work has been done and you can print an insane number of prints before needing new plates. Your image quality is also extremely high with offset printing - It used to be dramatically higher than with digital, but that gap has closed. Nevertheless, you still get great quality in large quantities.
Digital Offset Printing Advantages
Circling back around to digital offset, if you want your project done fast, this is going to be your choice. Digital offset printing has a much quicker turnaround time than offset does. It’s cheaper for low volume projects (because it requires less time and labor). Your prints aren’t going to vary much if at all, and you have a lot more options as far as what you can print onto.
Possibly the biggest advantage of digital offset printing, though, is variable data printing. With variable data printing, each piece can be printed with different text or graphics (relayed from a digital file) without the press ever stopping or even slowing down. Obviously this is great for books, personalized letters and invitations, localized ad campaigns, etc.
When To Use Which
Given what we’ve discussed, here are a few basic guidelines for deciding whether your project is best suited for offset or digital offset printing:
- For cost-effective mass production of a single image, go with offset. That’s its main selling point.
- If you think you may want to print the image many more times – offset (because your plates are already made and unless you’re printing millions of copies, you probably have many more runs before you need new plates).
- If your quantity is low, you’re going with digital.
- If you’re customizing prints and/or wanting a wide variety of options to print onto (wood, plastic, different types of film and paper, etc.) – definitely digital.
- If you need your prints soon – digital, although this can get expensive if you’re summoning a digital offset printer to do an offset printer’s job.
Note: the colors you’re using may also be taken into account to determine the most cost-effective option, but experts will bring that to your attention upon speaking with you about your project.
Coming Soon: Digital Onset Printing
Now that we’ve brought you up to speed on offset and digital offset printing, we’ll soon be introducing digital onset printing. Check back soon for the amazing new possibilities this technology brings.
*The information in this post is in no way definitive and should only serve as basic background knowledge. Technology is constantly changing, and every project is different. It’s important that you speak in great detail with a professional representative before making a decision on the production of your project.
HP, hughdoherty.tripod.com
