One of the most common problems our customers notice with their delivered postcards is one or more streak-like marks on one or both sides of the card. But where do these come from and how can they be avoided?

1. The Issue

Following some examples of such print results:

A large white spot with blurring A large white spot with blurring to the side

Two parallel tracks, one with heavy paint rubbing, one with longitudinal smearing

Blurring resembling water stains

2. The Cause

Although it may appear that way, this result is not a printing error. The printed output does not show these marks when it leaves the print company – they only appear during the automatic processing of the mail.

In the sorting process, the postcards are conveyed at high speed and with equally high frequency along conveyor belts and between guide tracks. The acceleration and friction of the feed and transport rollers can cause the surface to heat up to such an extent that the marks shown above can appear.

In the usual production process using toner, “smudges” as with ink cannot occur at all. Here, the toner is burnt onto the paper by means of heat. Smudging is therefore not possible.

3. The Solution

As this is a postal issue, there is unfortunately not much we can do initially to get to the root of the problem. These traces can occur on all postcards sent by mail. 

However, if such an error is absolutely unacceptable even on single individual copies, there are two workarounds:

1) Offset instead of digital – In offset printing, there is the option of using printer's varnish, which seals a postcard in such a way that the risk of these marks can be minimised. However, it is important to remember that offset printing is slower and much less flexible when it comes to personalisation. 

2) Add an additional envelope - To protect the postcard from abrasion, it can be sent packed in an envelope. To do this, simply select the envelope in addition when creating the campaign. However, a postcard in an envelope naturally has a different advertising effect than a postcard.

We understand the frustration that comes with such an error when, after a long and careful design of colours and compositions, the result is suboptimal due to postal processing. The post office is of course aware of this problem, and we hope that in the future, ways and means can be found to mitigate the risk of such traces.