Specialty Printing Processes
Specialty Printing Processes
It catches your eye. You can see that there is something unusual. The type looks shiny. The logo is puffy. You just want to touch it …
In today’s world of over-communication, it often takes more than ink on paper to make your piece stand out. The average consumer won’t be able to put their finger on what it actually is that catches their attention, but you surely will.
Thermography
You have seen it on business cards, often just black on white. The design might not have been impressive, but the raised typography made the carrier of the card most proud.
There is a reason why thermography is often called “imitation engraving” and with the right design, it can make your cards, invitations and other printed pieces look stunning.
How it works
Thermography is a heat activated process. A special unit is attached to the offset press and after the original printing process, while the ink is still wet, the paper is transported through the thermography unit. Next, the whole sheet is spread with a special thermography powder. While the small granulates stick to the wet ink, a vacuum sucks the loose granules up and stores them for re-use. The powder is now fused with heat into a raised, usually glossy, enamel-like look. The actual thermographed area has a slick, waxy feel to it.
Colors and inks
There are two types of thermographic powders used today: transparent and opaque. Transparent powders are the most commonly used and are available in various finishes. The color of the finish is determined by the color of ink used underneath the transparent powder. Opaque powders are offered in metallic and a variety of primary and pastel colors. There are gloss, semi-gloss, matte and dull finishes available in both powder offerings.
Paper choices
With weights ranging from 20 lb. writing to 100 lb. Cover, all types of paper stock can be used for thermography. For the best results though, a smooth finish reflects the raised effect better than a textured finish. Too much texture in the paper will also interfere with the vacuuming of the loose powder and might leave unwanted residues.
Thermography works especially great on colored stock, since the powder gives the ink a more opaque look, which can be a definite plus, especially when printing smaller type or on darker sheets.
Engraving
You see it on wine labels and fine stationery, invitations and business cards. Strong lines and a sharp definition. Slightly raised ink. Mainly printed in one color. Engraving.
With your trained eye for details you can easily see the difference between thermography and engraving. The lines are much finer, there is more detail in the images and the inks have a more chalky feel.
How it works
Unlike thermography, engraving is done on a separate engraving press.
The design is mechanically or chemically etched into a printing plate – also called a die. The finished plate is filled with ink, ensuring that all sub-surfaces are filled, then the plate’s surface is wiped clean. Slightly moistened paper is pressed against the plate with immense pressure, forcing the ink from the sub-surface onto the substrate. This produces the characteristically embossed feel of engraving. Steel plates are used for longer or repeat print runs, such as letterheads, stamps and money, while less expensive copper plates are used for one-offs and shorter runs.
Colors and inks
Even though most engraved pieces you come across will have more subdued colors like black, navy and gray, engraving inks are available in a full spectrum of colors, from pastels to fluorescents. These colors are usually mixed to correspond with the Pantone system. Engraving inks are much more opaque than offset ones, which means that you cannot build colors in CMYK like you’re used to. On the other hand, they make for great readability, even with little contrast to the paper color.
Paper choices
Due to the opacity of the ink, engraving is a great process for colored stocks, with smoother sheets being preferable. Weights can range from very light to very heavy stocks. Be aware that due to the tremendous pressure during the printing process, there will be a slightly indented impression on the back of the sheet, which naturally is more obvious on lighter sheets.
Paper choices
More appropriately, we should call this section “substrate choices.” Screen printing is not limited to paper, but can lay down very thick layers of ink onto almost any surface, including fabric, plastic, metal, paper, leather, wood, glass, ceramic, you name it. So when it comes to paper choices, your options are literally unlimited.
When used for the right project, thermography, engraving, letterpress printing and screen printing are four ways to make your project get the attention it deserves. If vivid ink color and texture is required for a hand-touched look, letterpress is ideal. For opaque ink coverage and a variety of substrates, consider screen printing. These various printing processes create a unique look and feel to make your effort look special. They can create stunning detail and texture for your work and make your design stand apart from the crowd.
