Envelopes have typically been printed either flexographically (rubber or plastic printing plate) or offset (metal plate). Those two processes are still the most common for the vast majority of envelope printing. In a future article, I will break down the difference between them and how one might choose one over the other. Today’s article however deals with the world of digital printing and how that can be used to your advantage for 4 color envelope printing.
Flexographic printing for envelopes is generally only economical on larger runs of around 75,000 or more. Since digital is only economical on smaller runs, we will only focus on comparing it to offset printing. Offset printing (or lithography – same thing) is based on the principle that oil and water don’t mix. The image to be printed is burned onto a metal plate. That image is then transferred (or offset) to a printing blanket which, in turn, transfers it to the envelope to be printed. During the actual printing process, the oil-based ink adheres to the image area on the plate while a steady stream of water covers the area of the plate without the image in order to keep that free of ink.
Digital printing is done electronically. There are no printing plates. The printer automatically sends out the proper mix of colors to achieve the image that was programmed. In the world of envelope printing and envelope converting, digital printing is only economical on very small quantity jobs – generally under 5,000. The quality is comparable to offset although most prefer offset or lithographic quality and there are fine differences.
From the sole standpoint of quality, the one possible advantage of digital printing is that there would be less variation over the course of the print run given the fact that offset printing requires continuous fine adjustments in the ink/water mixture. For envelopes however the advantage of choosing digital printing over offset mostly boils down to cost. It’s much less expensive to set up and run a job digitally.
So, the fewer envelopes you require, the more it makes sense to print them digitally. Once the quantity gets to around 5,000, offset becomes more advantageous cost-wise and as the quantities increase, the unit cost of offset printing decreases significantly. Digital printing unit pricing stays relatively constant regardless of the increase in quantity.
Elite Envelope can provide either type of printing with the additional advantage of being able to print digitally on flat sheets for subsequent envelope converting under one roof.