Whether you are just getting started with digital printing or are interested in exploring new avenues, your choice of ink is important. Everything from your ink configuration to its chemical composition will impact what you can do and what results you can achieve.
There is no single ink that can accomplish everything, and no printer which can accommodate every type of ink, but if you know what you need to do, you can narrow down the essential elements for your business.
What is an Ink Configuration?
Any digital printer you buy will have a limited number of ink channels, commonly four or eight, and each channel can deliver one type of ink. Before choosing a digital printer, you will need to decide which inks you want to install in each channel, as this will determine the type of work you can produce and how quickly you can print.
Ink Colors and Types
Before we look at different ink technologies, here are a few categories that are common to almost every ink technology.
Vibrant colors and smooth gradients allow your graphics to shine.
This is the fundamental four-color configuration you will find in virtually every color printing solution. CMYK stands for cyan, magenta, yellow, and black*, and with these four colors, you can produce most color applications to a good standard.
*Why does K in CMYK mean black?
K refers to “Key” or “Key Plate,” a term from manual printing processes, meaning the registration plate to which the other plates (C, M, and Y) are aligned.
You may encounter lighter shades of ink for cyan, magenta, and black, often abbreviated as Lc, Lm, and Lk. These help to produce smoother gradients as one color blends into another. For example, when reproducing faces and skin tones, there are often several subtle shades of similar colors – using light inks lets you produce a more realistic result.
It is possible to add additional primary colors like red, green, or orange, to your ink set. When printing with CMYK alone, certain shades of red or green are difficult to match accurately. For most printing applications, this isn’t an issue, but when you need to match a client’s brand colors, it becomes more important. Adding additional colors of ink lets you extend your color range, or “color gamut,” and match colors with greater accuracy.
If you print exclusively on white media, you can create most products without needing to use white ink. However, if you wish to add window graphics to your product line, you will likely need to print onto transparent or cling vinyl. In this case, white ink adds a base coat which helps make the graphics stand out. Similarly, if you are printing directly to a dark substrate, you will need a white undercoat to make the graphics clearly visible.
GLOSS AND SPOT UV INK
Gloss, or clear ink, is a transparent ink used in UV printing. This can be directly applied like any other ink, with great accuracy. With gloss ink, you can add spot gloss and 3D textures to your print output letting you produce interesting effects, simulate embossing, and even print Braille text with greater ease than with manual processes.
If you’d like to add more special effects to your prints, metallic ink is another good option. With metallic silver ink, you can add silver highlights to your output or enhance CMYK graphics with a metallic undercoat. You can also achieve a metallic effect by printing onto a metallic material, leaving the unprinted metallic details to show through.
When branching into more specialist printing applications, one of the key issues you could face is the ink’s ability to adhere to the substrate. Materials like aluminum, stainless steel, glass, and certain plastics can prove challenging regardless of the ink technology you choose. Primer can be applied manually prior to printing, but you can also choose to configure your printer with a printable primer, letting you prime the print area with greater precision, thereby saving time and cost.
Resin inks are multi-purpose inks comprised of water-based liquid, resin and pigment ink colors. Resin inks are odorless when printing, have very low VOC (volatile organic compounds) levels, and do not require an off-gassing period prior to lamination, making these inks ideal for interior signage and décor applications and for high-volume production runs.
SOLVENT & ECO-SOLVENT INK
Solvent inks consist of pigments suspended in an oil-based solution. True solvent ink is high in VOCs (volatile organic compounds) and often results in an output with a noticeable odor. Eco-solvent ink, on the other hand, uses refined oil extracts that deliver several benefits, being biodegradable, low in VOCs, and suitable for a wide variety of applications.
UV ink is applied by a print head and immediately cured using UV lamps. This results in a highly durable finish, and because there’s no time for the ink to absorb or bleed into the substrate, crisp quality is virtually assured, whether you’re printing onto vinyl, plastic, wood, metal, or almost any other substrate. Because of this versatility, it is a popular choice for both direct-to-object printing and wide-format roll-to-roll printing.
Ink Certification and Regulation
Most commercially available inks are required to meet standards for chemical safety. These certifications are awarded by official bodies and include accreditations like OKEO-TEX Eco Passport and GREENGUARD. Although most inks will be suitable for typical print applications, some clients, like schools and hospitals, are subject to more stringent rules. If you are targeting these clients, it pays to consider a digital printing ink that is appropriate for those environments.
Many novice print professionals are tempted to cut costs by buying inks made by manufacturers other than those approved by the company that developed the hardware. Though these inks can be cheaper, this is a short-term saving. Since the devices are only designed to deliver a certain formula of ink, inks by third parties can gradually damage the printer and result in unnecessary downtime and repair costs. Also, most hardware warranties will not cover damage caused by the use of unapproved inks. Finally, there is no guarantee that these third-party inks have passed the certification processes mentioned above.