Thursday, January 28

4 Principles of Flexographic Printing

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Flexography is an old form of printing but then again, it’s a modern version of letterpress printing. So, the old really has become new again. Flexography is over a hundred and twenty years old, yet it and continues to be an effective printing process that can meet the specific needs of some companies and industries. Sometimes it is also known as flexo and its flexibility means that it can be used for a variety of commercial printing needs.

Flexography can be used on almost any type of substrate. That includes corrugated cardboard, cellophane, plastic, label stock, fabric and metallic film. It utilizes quick-drying, semi-liquid inks and is great when there is a need for printing large areas of solid colour. This also makes it popular as a medium for printing on the non-porous substrates required for various kinds of food packaging.

1. How it works

Flexography or flexographic printing uses flexible photopolymer printing plates wrapped around rotating cylinders on a type of printing press called a web press. The advantages of this is that the inked plates have a slightly raised image and can rotate at high speeds to transfer the image to the substrate like cardboard or cellophane.

These inks can also print on many types of absorbent and non-absorbent materials. As a result, flexographic printing is well-suited to print continuous patterns, such as for gift wrap and wallpaper, and as noted for many food products as well. One of the best things about flexography is that unlike the individual sheets of paper used in traditional offset printing, the rolls of material used in flexography allow large orders to run with few interruptions to reload the substrate.

2. Advantages of flexography

Flexography is very fast and it can run printing jobs at extremely high press speeds. It prints on a on a wide variety of substrate materials like corrugated cardboard, cellophane, plastic, label stock, fabric and metallic film.

Flexographic printing has a relatively low cost when it comes to both purchasing equipment and on-going maintenance. That’s helped as well by the lower on average costs of most consumables. Flexography and flex storage solutions are perfectly suited for long runs as well an all printing and added processing like varnishing, laminating and die cutting can be done in a single pass.

3. Disadvantages of flexography

The downsides and disadvantages of flexography is that the cost of the initial printing plates can be expensive sometimes, but they pay off in the long run because of their ability to last for a long time when they are properly cared for.

It also takes a bit longer to set up more complex jobs if the added processing like varnishing, laminating and die cutting that may take several hours. There could be some wastage on the set-up too, as this process does use a large amount of substrate material. Finally, if any changes are required, they take time and may cost a little more money.

4. Designing for flexographic printing

Flexographic printing has specifics relating to types of proofs, template and die cut specifications, issues with knockouts, drop shadows, fonts, tints, ink colors, image resolution and image formats. That means that the design and file preparation can affect the quality of printing you get from flexography.

In turn, this means that it is important to master its specific requirements which differ from the more familiar offset printing. The minimum font sizes used for both positive and reversed serif types are based on the type of web press and whether you are printing to specific substrates like corrugated coated paper or polyester film.

There are also different types of fonts that must be used in flexographic printing and the minimum range is 4 point to 10 point type, and reversed types can be tricky to use in flexographic printing.


About Author

Rodney Seif

Staff writer / Lifelong musician / Unapologetic hipster