What do I need to know about Custom Printing on bags, signs and packaging?

At Custom Poly Packaging, we print your poly film products on a press using up to 4 Pantone spot colors. We also do screen printing on coroplast material that is capable of accomplishing 4 color process printing (CYMK).

Plates

Photopolymer Flexographic printing plates are used to print your custom flexible packaging. They are made from your art, are owned by you and stored under special conditions at Custom Poly Packaging to be used in the manufacture of your custom flexible packaging. Plate life expectancy is about 3 years or 500,000 impressions, but this is only an estimation.

The plates vary in size depending on the size of the bag to be printed. Depending on your size requirements, a press cylinder of the appropriate diameter is selected and a number of prints per plate is determined. This often means that your bag will not be an even measurement. For example, a 12x16 bag printed with registered printing will actually be 12.205" wide due to the constraints of press cylinder diameter and image repeat per plate. 

Registered Printing

Registered flexographic printing means that the image printed on your bag will always appear in the same position from one item to the next. For example, when you check out at Target, the red Target logo is in the same place on every shopping bag.

Registered printing is accomplished by synchronizing plate size, image repeat and bag size to ensure that the image is pressed on the film at regular intervals that will ultimately end up at the same place on each finished bag after the film is converted into its final product form. For example, by setting our 12x16 bag's actual width at 12.205" with a plate that will print the image twice per turn of the proper cylinder, the image will always end up in the same  place on the finished bag.

Random Printing

Random flexographic printing can be slightly less expensive than registered print, but the image(s) will appear multiple times on each bag and will change position in a vertical or horizontal direction depending on whether the bag is bottom seal or side weld. There will be many bags with a partial image at the edges of the bag since the bags will be cut and sealed without regard to the position of the image(s).

Slug Changes

Mid-run plate or slug (small plate) changes are also available. Because each plate represents a certain amount of cost, it is more economical to run a single bag type, size, thickness & feature(s) that is printed with multiple similar print images and changing only the part of the overall image that is different. For example, an order for 100,000 bags [all the same type, size, thickness, feature(s)] may be composed of 10 jobs of 10,000, each with a different UPC bar code and product name change in the graphic image. The background, company name and info and other graphics that remain the same can be printed from the same plates for the entire 100,000 print run. The product name and UPC bar code can be changed by using a new plate or two that will print in combination with the common plate(s).

Sometimes when a plate changes, an ink color will also change. There are some specific guidelines you'll need to know when designing your graphics to take advantage of combination (combo) runs of a bag. Please call us to discuss your project. This will save you time and money when the graphics are created.

Process Printing on Coroplast Signs

Because coroplast signs are printed using screen printing rather than a press, the color capabilities for these signs is very different. Process printing combines Cyan, Yellow, Magenta and Black (CYMK), separating the final image into print layers and then layering the four colors to create a full-range color effect. This is the same technology used by most current color ink jet printers.

Back to Educational Resources Page

Call Today, toll free, 1.800.548.6603 or

Request A CUSTOM Flexible Packaging Quote Online