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Introduction to Offset

Offset printing, also called lithography, uses a large printing press with a series of printing plates that transfer ink onto paper, which is then cut, folded, and bound to form a final product.

When you think of offset printing, think of the word transfer. Each step in this printing technique involves the transfer of images (text and art) from one material to the next. First, your images are digitally transferred onto a set of plates, which collect ink to transfer your images onto a rubber blanket that (holds mic to the crowd) transfers images onto paper.

There are two primary types of offset printing, sheet-fed and web. The most common alternative to offset printing is known as digital or print-on-demand.

Sheet-Fed Offset
Image Source: Heidelberg
(PrintNinja uses this type of machine) Sheet-fed machines use pre-cut sheets of paper, called parent sheets, that are fed through the printing press one sheet at a time. They are best used for short or mid-range runs (250 - 10,000).

Pros:
• Highest quality
• Wide range of options
• Low per-unit costs
Cons:
• High set up costs
• Medium minimum order sizes

Web Offset
Image Source: Print Business
Web presses use a roll of paper that is continuously fed through the printing press. They are far more complicated than sheet-fed presses and can be as large as an entire building. Web presses are used for high-volume printing (10,000+).

Pros:
• Extremely low per-unit cost
Cons:
• Extremely high set up costs
• Large minimum order sizes
• Lower quality than sheet-fed

Digital (POD)
Image Source: ZDnet
Digital printing (also known as Print-On-Demand or POD) is not an offset printing method, but it's a good one to understand. Digital printing uses equipment similar to a large home laser or inkjet printer. This approach is best used for small runs (1-150).

Pros:
• No set up costs
• No minimum orders
Cons:
• High per-unit costs
• Less consistent color / quality
• Fewer options


What Can You Print with Offset

Offset printing can be used to print on paper, cardboard, plastic and even chocolate. This printing method is a popular choice for card and board games, record jackets, and multi-page projects. Games and books follow the same printing process, but post-press is where the similiarties end.

For the rest of this journey we will be focusing on four-color sheet-fed offset presses, the workhorses of the printing industry and the machines used by PrintNinja’s factories. These presses use four colors of ink —cyan, magenta, yellow, and black (CMYK)— to produce the vast majority of full-color projects printed worldwide.

4-Color Press Hedelberg Sheet-Fed
A four-color sheet-fed press machine