Digital print envelopes: a complete guide for direct mail campaigns

When planning a direct mail campaign, there are lots of things to think about. As well as the size of your mailers and the type of printing you use, there is the question of how to package your items.

For many organisations, envelopes are the clear solution. But these don’t have to be plain white paper. With digital envelope printing, you can add colour and vibrancy to your campaigns that get your mailers noticed, help boost open rates and provide better visibility for your brand.

In this guide, we’ll explain why digital printing matters, how it works and what considerations you need to keep in mind for your envelopes to ensure the best ROI for your mailers.

Why digital print envelopes matter

The envelope is the first impression your audiences get of your direct mail campaign, so you have to make a positive impact. If it’s bland and uninteresting, it’s more likely to end up in the recycling without being given a second glance.

An enticing printed envelope, on the other hand, can greatly improve open rates by making recipients curious about what’s inside. This means a much higher chance of a positive response rate.

According to JICMAIL, the average response rate for ‘warm’ direct mail – items sent to people who have an existing relationship with the company – stands at 7.2 per cent and offers an ROI of £9.00 – compared with a 0.9 per cent response rate and ROI of £3.20 for cold mail.

Having printed envelopes therefore helps with brand recognition as soon as it appears on the recipient’s doormat.

How digital printing for envelopes works

There are a few options available when printing envelopes. Picking the one that works best for your campaign’s needs and circumstances ensures you’re striking the right balance between quality, cost and speed. Here’s what you should consider.

Inkjet printing

Most useful for high-speed, large-volume print runs, inkjet printing is well-suited to less complex print requirements such as address and simple graphics. It can’t provide the quality or detail of other options, but makes up for this by being fast and efficient.

Laser/toner printing

For items where crisp, high-resolution graphics are required, laser printing is often the way to go. It’s slower than inkjet, but should be considered for smaller runs where a high level of detail and quality are more important than speed and volume.

Variable data printing

Personalisation is one of the biggest difference-makers when it comes to boosting engagement with direct mail. Variable envelope printing allows you to do this before the mail is opened, allowing you to tailor copy and graphics based on a user’s demographics or interests to increase the chances of your mail getting noticed.

Key design and postal constraints

When deciding on envelope printing design, it’s important to take into account the practical needs of postage and ensure your designs are planned accordingly. Here are a few things to be aware of.

Address placement and window envelopes

When using windowed envelopes, any printed design will have to be mindful of their size and location to ensure readability. On DL, C5 or C4 envelopes, the standard window size is 90mm x 45mm, with positions as follows:

DL – 19mm from left x 18mm from bottom

C5 – 20mm from left x 60mm from bottom

A4 – 24mm from left x 213mm from bottom

As a good rule of thumb, all design elements should be kept at least 5mm clear of the window edges.

PPI printing requirements and print safe zones

In order to maintain clarity for postal provider barcode readers and avoid the risk of envelopes being rejected – especially when using Printed Postage Impression (PPIs) – there are a few guidelines to follow. These include:

PPIs must be in the top right corner with 5mm of clear space around the PPI mark.
A standard Royal Mail PPI box should be 39mm wide x 23mm high.
It must be printed in black or a dark colour that contrasts with the background.
Keep a clear zone 15mm from the right-hand edge and a 70mm x 35mm clear zone around the address window to allow for Royal Mail optical readers.
There should be no patterns, logos or coloured backgrounds behind the address or PPI.

Sustainability, materials and inks

Sustainability remains a major concern among many consumers, so it’s important that printed envelopes reflect this. Using PEFC-accredited, recyclable paper that is clearly marked as such on the envelope helps with this, as it shows a commitment to sustainability. Using a printer that takes eco issues into account, such as modern equipment that decreases power consumption and using electricity from sources such as solar panels can also help boost green credentials.

Fulfilment and machine insertion: what to watch out for

If you are planning on using envelopes for your direct mail campaigns, the next step after printing is fulfilment, including finishing and enclosing services. The most cost-effective way to do this is with machine enclosing, but there are a few requirements to be aware of to make this possible.

Envelope and insert sizes

We offer machine fulfilment services for envelope sizes including DL, C5, C4, C6 and Square. For machine insertion, the main consideration is that the envelope is ideally 15mm larger than the items being inserted, to enable the machine to grip the edges of the envelope.

Thickness and weight

The maximum thickness for machine envelope enclosing is 6mm. We also apply a limit of 350g for machine printing, as items heavier than this are likely to exceed 6mm. What’s more, the envelope will no longer provide sufficient protection for such items. In these cases, we recommend using a jiffy bag, polywrap or bookwrap to avoid damage in transit.

Envelope sealing

There are three main types of sealing options for envelopes, which can affect whether or not hand fulfilment is required. The choices are:

Gummed: The standard envelope for machine enclosing.
Self-seal: This has a third flap that houses the sticky enclosing part, which makes it incompatible with rotary envelope feeders.
Peel and seal: These require an operator to remove each glue strip and manually close the envelope. While these can be machine enclosed, it is a slow and more expensive process, making it less cost-effective for smaller runs.

Choosing the right printed envelope: cost drivers and pain points to avoid

Selecting the right printed envelope for your direct mail may not seem like one of the major decisions, but getting it wrong can greatly increase costs and the time taken to complete the process.

To begin with, you should ask yourself what your goals are. Do you want to send to as many people as possible, or is it a ‘high investment’ direct mail piece, sending to a small, select group that offers higher open and response rates?

Envelope designs will be a lot cheaper to produce if no bleed is required (i.e. if the design doesn’t extend to the outer edge) and ink coverage is no more than 30 per cent. This allows for off-the-shelf envelopes to be used, saving time and money.

Fully-printed designs with bleed, on the other hand, require bespoke envelope printing techniques where they’re printed before being shaped into envelopes. This is a highly expensive option due to the time and machine setup costs involved. However, it can create vibrant designs that really stand out.

You should also think about your physical materials. Poor paper or ink choices can lead to jams or sticking during printing, while incorrect packaging or labelling can cause delays later in the process.

You can avoid these pitfalls by partnering with an expert envelope printing provider who can advise and guide you through every stage of the process, from print design to material selection, ensuring your envelopes look professional and perform perfectly.

Get in touch with The Mailing People today to find out what we can do for you.