Like most industries, the envelope industry has it's own technical terms or jargon.
The following list summarises many of the terms and definitions used;
These envelopes make retrieving and recording information very easy.
Usually, promotional material is printed on the perforated reply slip flap, which can then be filled in and returned inside the envelope once completed.
Bangtail envelopes are widely used by charities and fundraising organizations to facilitate the collection of donations, where the design can be useful for protecting the privacy of the donor’s details.
There are two styles of Bangtail envelopes:
1. The bangtail ‘flap’ has its reply slip attached to the flap of the envelope.
2. The bangtail ‘back’ has a reply slip attached to the back panel of the envelope.
These can also be known as greeting card or invitation envelopes, due to their tradition of being used in the greeting card industry for sending personal notes and cards.
The origin of the use of the diamond shape for envelopes is not certain, but could perhaps have been used as a handy alternative to simply wrapping a sheet of paper around a central rectangular area such as a folded letter or an invitation. With this style, you will be left with an arrangement of four diamond shapes flaps on the reverse side, which only need to be sealed to provide a tidy, paper-efficient way of producing an envelope.
Today, banker envelopes are very commonly used.
Basket weave envelopes feature a distinctive weave effect finish, traditionally used for heavyweight 115gsm manilla papers.
Strong and secure, these envelopes are suitable for all general purpose mailings where durability is important.
This crisp, quality paper has tear-resistant qualities which withstand even the roughest handling and ensures protection for all contents. All this makes these envelopes the ideal choice for those more bulky documents and catalogues.
Our Purely Everyday range features a number of basket weave envelopes.
Did you know, using envelopes with a textured paper will lend a certain quality and charm to your mailings? Explore our Premium Business range for more classic textures, from a timeless laid, to the beautiful wove and flawless digital smooth options.
Our Personalisation Service can produce any size and shape of envelopes or packaging solution, from almost any kind of material, printed or unprinted, according to your specifications.
Working closely with you, we will meet your every requirement and create unique, tailor-made envelope and packaging solutions to elevate your communications, ensuring your messages resonate with the consumer every time.
Our team are happy to give you all the support you need to ensure your creative vision hits the mark, and will collaborate with you to develop an idea from the start, nurturing it through to a reality utilising the best materials and techniques available.
Learn more about our bespoke capabilities in our Personalisation section, and get in touch today to design the perfect envelope for you!
Blank fed envelopes are manufactured from large flat sheets of paper which are punched out with a die cutter in the shape of an unconverted envelopes, producing a blank. A blank converting press then accepts the die-cut paper and it is folded and glued during the manufacturing process to form the finished envelope.
If blank fed envelopes require over printing, this is usually carried out prior to cutting out the envelope blank. Similarly, if a window is required, this can be carried out as a separate operation once the envelope blanks have been cut and prior to the folding and assembling of the finished product.
Generally coming in a pocket format, these envelopes would usually utilise a 120gsm paper and 1000 micron backing board, and are the ideal choice for preventing valuable or fragile documents from getting damaged, creased or bent in the post.
Examples of contents that require a board back envelope include certificates, brochures and legal documents.
Our board back envelope collection boasts an excellent range of heavy duty products, available in a combination of white, grey or manilla. Made using a durable backing board and heavyweight face paper, these will guarantee maximum protection when posting bendable items. Also ultra secure, these products feature a peel and seal closure: the most secure method of sealing, and the option of a ‘do not bend’ precaution printed on the face.
BREs are used by businesses to encourage customers to reply to them without the customer having to pay the Royal Mail's postage cost themselves.
These envelopes are normally an undersized DL (105x216mm or 102x216mm) or an undersized C5 (155x220mm) size.
Made entirely from a hardwearing card, these provide a rigid and hardwearing packaging solution that will guarantee extra protection and support for all contents, eliminating any risk of creasing or bending.
Explore our Premium Optima Envelopes for a superb range of heavy weight card envelopes spanning 7 different sizes. Coming in a pristine bright white shade, these are the ultimate in envelope quality.
Sometimes, the term ‘card envelope’ may refer to an envelope that you would send a greetings card in: in this case this would refer to our invitation envelopes.
The term ‘colour wash’ will often relate to the internal opaque of an envelope. our Envelope Insights section for more information.
A colour wash can be achieved by mixing an ink with another liquid, which is then used to do an all over wash on an envelope, creating a solid colour.
This would normally be applied using flexographic printing.
We offer a number of products with a colour wash interior within our Purely Everyday range.
Corn starch window film is used throughout our Purely Environmental Evolve Recycled Range to ensure it is both recycled and recyclable.
A matt film with a normal brightness, our corn starch film is available in a 29 micron thickness. Made from annually renewable plant resources which will biodegrade in 30 days, it has an excellent moisture transmission rate, high natural dyne level, excellent scratch resistance and high transparency to UV light. Besides all this, it offers an environmentally friendly alternative to plastic window films, and will not affect the paper recycling process!
With a variety of envelope manufacturing machinery to produce large-run and short-run printing, they have the most modern envelope manufacturing capabilities and a dynamic range of envelope printing and folding equipment which enables them to produce any type and size of envelope.
Diamond offer versatile, modernized high-speed and blank fed production that prints up to 8 colours, for superior manufacturing and accurate registration at a cost saving to the client.
This technique can be used to put holes through envelopes to serve for storage and filing purposes, or so that the recipient can confirm that all contents have been removed.
Drilled holes are most common in internal mail transit pockets, where they are used to check for inserts.
Flexo printing was invented in Liverpool in the year 1890, when the first press was built by Bibby, Baron and Sons. By the early 1900s other European presses using rubber printing plates and aniline oil-based ink had been developed.
This method of printing is used for large quantities of envelopes which are not up to the quality of litho printing. Despite the fact that quality is traditionally lower that litho printing, this is the most cost effective method for printing larger runs.
Utilising a flexible rubber or photopolymer relief plate that wraps around a cylinder, usually as part of the envelope production machine, flexo printing is essentially a modern version of letterpress and can print onto almost any type of substrate including plastic, metallic films and cellophane, as well as paper.
Here at Blake, we use flexo printing for a variety of purposes.
A smooth, glossy paper that is air, water and grease resistant, glassine is usually available in densities between 50–90 g/m². It is translucent unless dyes are added to colour it or make it opaque.
A unique grade of paper, it has many desirable properties and benefits, making it a popular choice. It is environmentally friendly, coming from 100% sustainability-managed forests and is also 100% recyclable and biodegradable.
This type of window film is often used in our bespoke envelopes.
Different weight papers are used for different purposes, but usually the higher the grammage and the thicker the paper is, the better quality it is. Our envelopes and packaging products range from 80-200gsm.
See below for all the standard paper grammages and what these are used for:
80-100gsm - Copy Paper, Printer Paper
120-170gsm - Parchment Paper, Premium Printer Paper, Card Inserts, Luxury Paper Pads, Background Papers, Foiled Papers, Envelopes
200-250gsm - Average Weight Card, Stamping Card, Embossed Card, Mirror Card, Printing Card, Decoupage Sheets
260-290gsm - Pearlescent Card, Topper Sheets, Designer Card, Kraft Card, Card Blanks
300-350gsm - Heavyweight Card, Luxury Card Inserts, Hammered Card, Centura Pearl Card, Luxury Designer Card, Luxury Topper Sheets, Decoupage Sheets
Gummed envelopes have a strip of water soluble gum adhesive which requires moistening to seal. This gum is usually made from a blend of synthetic resin and dextrin, so is therefore biodegradable.
This is the most common sealing method and is always used for mailing envelopes as only gummed envelopes are suitable for automatic machine inserting, where the sealing can be performed automatically by the mailing machine.
If stored in the correct conditions, gummed envelopes should last for a number of years.
Many of our Purely Everyday envelopes are gummed.
Other sealing types include self-seal and peel and seal.
Gusset envelopes provide a spacious and convenient approach to sending bulky documents such as catalogues and reports.
Now becoming increasingly popular for ecommerce fulfilment, these enable businesses to reduce packaging waste whilst ensuring their produce arrives safely and with minimal carriage cost.
Our gusset envelope collection spans over 52 different products, from coloured and board back options, to tear resistant and recycled envelopes, and is sure to have the perfect choice for you however specific your requirements!
Blake now have 2 Halm EM5000 litho overprinting machines which are equipped with 5 printing units, four colours face and one reverse.
These have the ability to print 4 colour process to the face of the envelope at the same time as printing 1 colour on the reverse, so that there is no need to run a second pass for the all important return address or message.
With its central impression cylinder, the EM5000 machine can hold close registration across a variety of envelopes, giving an outstanding print result. The EM5000s are also equipped with UV drying capabilities allowing for coated papers to be printed.
Hot melt sealing can also be known as super seal, strip seal or peel and stick.
Hot melt sealed envelopes are the most common option of peel and seal envelopes we stock. Due to their sealing properties, hot melt peel and seal acts as a tamper proof security seal as it is impossible to open the envelope without tearing the flap.
The other form of peel and seal adhesive is cold melt. This method of sealing is similar to self-seal latex, with one band of adhesive which is covered by a large silicone paper strip. Envelopes with cold melt peel and seal normally have a shelf life of 2 years.
These can also be known as a banker or greetings card envelope, due to their tradition of being used in the greeting card industry for sending personal noted and cards.
This style of envelope is the perfect choice for any special event.
Explore our select array of invitation envelopes within our Purely Everyday range, encompassing 29 handy sizes!
It measures 40-50microns as opposed to the standard 22mm.
Window envelopes from our Premium Business, Premium Office, Premium Pure and Premium Postfast ranges are produced with a 50 micron laser window film, making them guaranteed to withstand the heat of both colour and mono laser printers and digital machines.
Other types of window film include a standard film, or a biodegradable option.
Featuring a signature trapezium flap and a gummed flap for automatic sealing, this style of envelope is required when using folding and inserting equipment. Slightly larger than the standard envelope sizes, mailing envelopes provide the necessary extra space required for the machine to faultlessly insert any contents.
With distinctive features and laser windows, these envelopes support the latest digital print technology and are perfect for processing mail at speed, as designed to run easily and efficiently on all mailing inserting machines with a consistent quality to avoid expensive machine down time.
Browse our extensive range of mailing wallets and uncover the largest range of machine inserting envelopes in the UK, offering all the most popular sizes, from DL to C4, with windows or non-windows, not to mention recycled options…
These envelopes are designed for full colour overprint, as their matt finish has a very noticeable effect on the appearance of the printed colour.
The coating on these envelopes keeps much of the ink from being absorbed by the paper, which produces excellent, vibrant colour.
See below for some of the common paper weights in both microns and grams, along with their traditional uses:
80-100gsm Copy Paper, Printer Paper
120-170gsm Parchment Paper, Premium Printer Paper, Card Inserts, Luxury Paper Pads, Background Papers, Foiled Papers, Envelopes
200-250gsm Average Weight Card, Stamping Card, Embossed Card, Mirror Card, Printing Card, Decoupage Sheets
260-290gsm Pearlescent Card, Topper Sheets, Designer Card, Kraft Card, Card Blanks
300-350gsm Heavyweight Card, Luxury Card Inserts, Hammered Card, Centura Pearl Card, Luxury Designer Card, Luxury Topper Sheets, Decoupage Sheets
Opaques can also be used to reveal a message through the window once the contents have been removed. We use this in both our Purely Environmental Recycled and our Purely Environmental FSC ranges to reinforce their environmental credentials.
Most interior opaques are printed in shades of blue or grey during manufacture. However, on special bespoke orders if the quantity is large enough, customers can have their own design opaque or specified Pantone colour. Some choose to incorporate names, logos or messages in the throat of the envelope.
Our blueprint opaque is the ‘mountain peak’ design, printed in Pantone 292 and consistent across the complete range. We also offer a few select lines with a grey opaque.
Each Pantone colour has its own individual number, allowing these to be recognised across the globe, acting as a colour language for designers, and the definitive language of colour.
At Blake, we use the Pantone reference codes for specifying printing inks.
All the artwork for our envelopes would be transferred using a PDF file.
There are two basic configurations of offset perfecting presses:
1. Using a convertible perfector. This features special transfer cylinders which are positioned between successive printing units, which flip the sheets of paper over after leaving the first impression cylinder, enabling the second unit to print on the reverse side. These presses have the advantage of also being able to carry out single-side multi-colour printing but simply adjusting the transfer cylinders so they are prevented from flipping the paper.
2. Using a blanket-to-blanket press. Used primarily in web offset lithography, where the impression cylinder is replaced in one printing unit by a second blanket cylinder directly beneath the first. As the sheet or paper web passes between the two blankets, both sides can be printed on to simultaneously.
The 3 most common types of envelopes are pockets, bankers and wallets.
When choosing the right envelope for your needs, decide where you would like the opening to be placed as there are different options available to you. Wallet and banker envelopes have the opening flap placed on the long edge of the envelope which is what defines the envelope as a wallet or a banker.
Wallet envelopes would normally have a trapezium shaped flap which is suitable for automatic mailing machines and can come in straight or slightly curved variations.
Banker envelopes can be identified by their triangular flap which is traditionally used in the greeting card industry and for personal use note/letter paper and cards. They can often be referred to Greeting Card or Invitation Envelopes, which you may have heard of.
Offering a convenient alternative to stamps or franking machines if you're sending large volumes of mail in the UK or internationally, Printed Postage Impressions (PPIs) save both time and money by enabling the postage to be printed directly onto labels or envelopes.
Our recycled envelopes are made from post-consumer waste. Covering a wide range of products, from our FSC envelopes, to the Flora, Nature First and Evolve options, providing you with everything you need to act responsibly and do you bit for the environment!
Our FSC range contains envelopes with some of the most recognised environmental credentials of the day, which are manufactured from fully certified paper.
Our Flora Recycled envelopes are a classic example of a recycled envelope, with a signature off white shade giving clear proof of their recycled nature, and a green opaque to further emphasise the environmental message.
Our Nature First envelopes are 100% recycled as well as FSC certified, and boast a bright white shade unusual in recycled envelopes, making them the obvious choice!
Evolve is a name well known in environmental circles. Stocked exclusively by Blake across Europe, our Evolve recycled envelopes are widely respected.
Winkler and Dunnebier are the main producer on envelope manufacturing machinery, and manufacture both reel fed envelope machines for envelope production.
A big competitor to W & D is F L Smithe who are an old established envelope machine manufacturer from the USA. Their RA800 and RA600 machines can also be supplied in reel fed and give speeds up to 800 envelopes per minute.
These small cuts are designed as 'tear points' for tamper proof security, and will cause the flap of the envelope to rip if the seal has been tampered with, ensuring greater safety for your mail.
Each of these flaps has its own strip of latex which, with contact to the other strip, will instantly and securely fasten the envelope flap. This method of sealing can also be known as dri-seal, press-seal and fast-seal.
The latex on self-seal envelopes is derived from rubber and ammonium substrate, and can therefore be classed as a natural product.
This normally only has a guaranteed shelf life of twelve months from date of manufacture but, if stored in the correct conditions, this may extend.
For optimum shelf life, self-seal envelopes must be kept in an equilibrium temperature. Here at Blake, we carefully control the temperatures of our warehouses throughout the year, providing controlled heating in the winter and cooling in the summer to maintain the ideal temperature for these products.
Security slits can sometimes be found on the flap of self-seal envelopes for security reasons. These will cause the flap to rip if the seal has been tampered with.
Unless time and care is taken to avoid it, the occurrence of set-off is very likely to occur where the ink coverage is heavy and/or strong colours are used.
However, there are several ways this can be eliminated or the effects can be minimised, such as running the print more slowly, using an anti set-off spray or UV driers, which can avoid the issue by ensuring the envelope is dry when going onto the feed table. For more information on this, see our UV Dryer section.
In offset printing, this term also refers to the unwanted transfer of ink to rollers and friction points throughout the printing press. This can be cause by the build-up of ink that isn’t properly dried of set over time, which can result on marking on the finished product.
In some cases, certain offset printing applications will add moisture back into the paper after it has been dried with an offset heat set drier, which, when it doesn’t have enough hardness, can end up breaking down the calcium carbonate in the paper which will lead to a build up and set off on the following jobs.
It is generally applied to Self Seal and Peel & Seal envelopes.
This can vary a lot, and often depends on the sealing type used. Here we share the different shelf lives of each sealing type we stock:
Gummed envelopes have a shelf life of a number of years, provided they are stored in the correct conditions.
Self Seal envelopes, on the other hand, have a strip of latex on each flap which is pressed together to form an instant bond. The latex on self-seal envelopes normally only has a guaranteed shelf life of twelve months from date of manufacture. If stored in the correct conditions, however, and with an equilibrium of temperature, this may extend.
Peel & Seal envelopes have a tear off tape revealing a strip of latex, which is pressed down to form an instant bond. There are 2 types of peel & seal sealing:
Cold melt Peel & Seal: Similar to self-seal latex, this has one band of adhesive which is covered by a large silicone paper strip. Envelopes with cold melt peel and seal normally have a shelf life of 2 years and;
Hot melt Peel & Seal: The most common option of peel and seal envelopes we stock, these have a narrow band of adhesive which is of a heavier gram weight than normal peel and seal and looks similar to double sided tape, guaranteeing up to 5 years shelf life.
Mailing houses usually prefer outside seams as they don’t catch on mailing machines, whilst printers may prefer inside seams for printing on the envelope reverse.
Envelope seams are typically permanently sealed for durability.
With mailing envelopes, the outside seams can be folded over the back flap: a technique not commonly requested in envelope manufacture but required by some insertion machines. Normally, the side seams are folded inside or under the back flap of the envelope in order to be as inconspicuous as possible.
Side seams can provide a large area for printing on the back of an envelopes, as seen in reverse face, collection and booklet style envelopes.
The size of the throat is measured form the top edge of the bottom flap to the fold line of the seal flap.
An envelope throat can be a critical design aspect for inserting machines, allowing the machine to insert contents into the envelope.
A tapered seal flap and throat contribute to better performance in sealing and automatic inserting applications, and the depth of the throat can be critical in influencing this.
Thumb cut envelopes have an open end: a handy feature allows for quick and easy access or removal of the contents inside.
These envelopes are designed to hold insurance policies, wills, contracts and other legal documents or, in other circumstances, can often be used for tickets or as negative preservers.
Topless envelopes offer a pleasant change from the norm and can give a distinct luxurious look and feel.
Set off is where the print on one envelope marks on another; a problem that can occur with most types of printing. For more information on this, see Set Off.
UV dryers can be used whenever is need of curing and drying inks where UV inks are in use, polymerising images onto screen-printed products as a part of the screen printing process. Printing with UV curable inks provides the ability to print on a very expansive variety of substrates, from paper and canvas to plastic, glass, metal and many other materials.
There are many advantages to UV drying inks. Perhaps the biggest of these is the lack of solvent fumes, which can contribute to air pollution and affect the health of those around. Not only this, but UV dryers also allow for instant drying of ink, which means that the product can be ready to continue working on immediately after being printed. Producing an excellent quality image, the screen printing process allows for a high level of detail, besides being a very clean, low maintenance printing method, therefore allowing for a higher level of production. As the inks that are used in this process don’t include a solvent that is evaporated, they have very high colourant and, sitting on the surface of the material rather than being absorbed, they give an intense colour quality.
Their wide ranging product portfolio is designed to meet changing customer needs.
With their innovative solutions and high-quality technologies, W&D are internationally synonymous for precision, speed and reliability.
It has been completely engineered with servo-technology to be the ideal replacement option for envelope manufacturers committed to improving the productivity and profitability of their high-volume production.
The W+D 102 RE is a productive fast-change-over, high-volume production system for stationery, transactional and direct mail envelopes.
The 212 is a two colour machine whilst the 214 prints four colours.
These envelopes are commonly used in all applications.
The 3 most common types of envelopes are pockets, bankers and wallets.
When choosing the right envelope for your needs, decide where you would like the opening to be placed as there are different options available to you.
Wallet and banker envelopes have the opening flap placed on the long edge of the envelope, and a banker envelope’s flap is a triangular shape, which is traditionally used in the greeting card industry and for personal use note/letter paper and cards. They can often be referred to Greeting Card or Invitation Envelopes.
On the other hand, pocket envelopes have their opening flap positioned on the short edge, which is what defines the envelope as a pocket.