If you’re in the packaging industry, then you’re probably already familiar with offset printing, as it’s an integral part of manufacturing as the packaging itself.
So let’s dive in and see what offset printing actually is!
What is Offset Printing?
Offset Printing, also referred to as offset lithography, is used to transfer inks onto various substrates, and it’s a cost-effective and efficient way to produce large volumes of packaging.
It allows for a wide range of customization options and can be used to produce both simple and complex designs.
What are the Types of Offset Printing?
When it comes to offset printing, it further falls into two types, such as
- Web-Fed Offset Printing
- Sheet-Fed Offset Printing
Web-Fed Offset Printing
Web-fed offset printing uses a continuous roll of paper, which is fed into the press in one continuous stream.
A continuous roll of paper is fed through the press, allowing it to print over 5,000 printed materials. Following the printing process, identical sheets of paper are cut.
This type of offset printing helps to manufacture the mass production of packaging, resulting in a faster production time.
Sheet-Fed Offset Printing
Sheet-Fed Offset Printing is a process where individual sheets of paper are loaded onto a press and printed one at a time.
It is an excellent machine for making small orders of packaging, reducing waste, and reducing resources at the same time.
What is Modern Offset Printing?
Modern Offset Lithography is a technique to print packaging material in a timely manner. It is done on a press, which is basically composed of 3 rotating cylinders and CTP Plates, further helping with the printing process.
Process of Modern Offset Printing
The first is a plate cylinder, which attaches to metal plates; the second is a blanket cylinder covered in rubber; and the third is an impression cylinder, which presses the paper to make contact with the blanket cylinder. This is how modernized offset lithography is done on packaging material.
Process variations of offset printing
Traditionally, offset printing was used to produce high-quality prints in large quantities. Here is a general overview of the steps involved in the offset printing process:
Prepress: The prepress stage involves preparing the artwork or design to be printed. This includes creating the printing plates, which are typically made of aluminum or polyester and contain the image to be printed.
Plate-making: The printing plates are made by exposing a photosensitive coating on the plate to UV light, which hardens the coating in the areas where the image is to be printed. A relief image is then left on the plate after the unhardened areas are washed away.
Setup: The printing press is set up with the appropriate paper stock, ink, and plates. The plates are loaded onto the press, and the press is adjusted to ensure the correct registration and color balance.
Printing: The paper is fed through the printing press, and the ink is transferred from the printing plates to a rubber blanket, which then transfers the ink to the paper. The paper may be printed on one or both sides, depending on the job requirements.
Finishing: After printing, the paper may be cut, folded, or bound into finished products such as books, brochures, or flyers.
Pros & Cons of Offset Lithography:
Here are some pros and cons of offset printing:
- High-quality printing: Offset printing is known for producing high-quality prints with sharp, crisp images and vibrant colors.
- Cost-effective for large print runs: Once the printing plates are created, offset printing becomes more cost-effective for large print runs compared to digital printing.
- Versatile: Offset printing can be used to print on a variety of paper stocks, including glossy, matte, and uncoated papers.
- Accurate color reproduction: Offset printing uses Pantone color matching systems to ensure accurate color reproduction.
- Large format printing: Offset printing can be used for large format printing, such as banners and posters.
- Longer setup time: Offset printing requires a longer setup time than digital printing. It involves creating printing plates and adjusting the press for each job.
- Limited customization: Offset printing is not suitable for printing variable data, such as personalized letters or customized brochures.
Corey Andrew works as a Content Marketer at MailerBoxes.us. He writes on dieline designs, packaging materials, and print technologies and how they benefit customers, company owners, package designers, and industry specialists in their Packaging.