About Dampers

Dampers are deceptively simple-looking but critical components in the ink flow of DTG & DTF printers.

Damper examples
Damper examples from Freejet (left) and OmniDTF (right) printers.

Dampers perform 4 functions.

  1. Provide a consistent ink supply reservoir for the printhead.
  2. Screen out any foreign material in the ink before it reaches the printhead.
  3. Act as a “pump”. There is round diaphragm behind the clear film side which has a spring behind it. As the printhead uses ink and the damper empties, the diaphragm gets pulled inward and starts compressing the spring mechanism. When the spring mechanism is pulled inward far enough, it eventually pushes back out, pulling ink in from the ink line and bottles.
  4. Dampen and regulate pressure changes in the ink line at the printhead as the printhead carriage rapidly stops and reverses direction while printing. When the carriage motion in one direction stops, the pressure momentarily increases and when it starts going back in the other direction, the pressure momentarily decreases, due to inertia. This is why the ink lines are not connected directly to the printheads. The dampers absorb these minor pressure deviations.
To maximize production and minimize scrap prints due to ink flow issues, we recommend replacing dampers after 6 months of use.

Damper failures can be caused by a number of things. The spring can start getting weak, so it doesn’t “pump” correctly. The O-ring that seals the connection to the ink line can start leaking air, resulting in banding or ink dripping from the bottom of the head. One of the clues you have a damper is failing is when the missing nozzles on your nozzle check prints keep moving around between head cleanings.

A full set of 8 dampers is included in the recommended Support Kit for your printer, along with other consumable parts that should be kept on-hand to minimize down-time.

How DTG Printing Works

OmniPrint's Freejet 330TX DTG printer

You may be familiar with screen printing. And even if you’re not familiar with it, the name gives you a clue – printing that is done using a treated screen as a stencil. But with Direct to Garment (DTG) printing, it’s a little more vague because the name doesn’t tell you much about the technique.

DTG is a process of printing graphics onto textiles and garments. It uses modified inkjet technology to print any type of graphic onto t-shirts, hats, bags, masks, jeans, and even shoes. It isn’t a complex process, but there are multiple steps and some key factors that contribute to print quality. Here’s an overview of the DTG steps:

  1. Create a design
  2. Load the design into a DTG Rip/Print App
  3. Pretreat the garment
  4. Dry the pretreatment
  5. Mount the garment
  6. Print the garment
  7. Cure the ink

Let’s take a closer look at these steps.

Create Your Design

One of the most important factors for a high quality DTG print is a high quality design file. Designers use graphic design software such as Photoshop and Illustrator to create their artwork in high resolution. These designs can be anything from geometric shapes to company logos to digital photographs.

Example graphic of a t-shirt print design.

Load the Image into a DTG RIP/Print App

After the design is complete it needs to be loaded into software that can RIP (raster image processing) the image, and then print it. OmniPrint’s software is called DirectRip. Before ripping the image, the print settings are configured. DirectRip simplifies this process by providing Environments that lets you simply select the type of garment that will be printed. Based on that Environment selection, DirectRip then loads a group of presets. Other parameters that can be set include resizing, positioning, and margins.

Pretreat the Garment

Properly pretreating the garment is another important factor for creating a high quality print. Pretreatment is like an adhesive that sticks to the garment’s fibers and allows the ink to bond to those fibers. The chemical composition of this adhesive pretreatment material also causes the “underbase” layer of white ink (which is used like a painter’s base coat of primer when printing on colored shirts) to quickly gel. This prevents the CMYK inks from blending with the white underbase and provides great color vibrancy.

Too much pretreatment can make the colors bleed and prevent the ink from bonding with the fabric’s fibers. Too little pretreatment and the ink will disperse too much into fibers, resulting in a light or dull print. 

Since getting a proper and consistent amount of pretreat onto each garment is critical to image quality, pretreatment machines have become very popular. Pretreatment machines provide consistency of spraying that can’t be achieved manually.

Dry the Pretreated Garment

Once the garment is pretreated it will be damp with pretreatment solution. It’s necessary to dry the print area before applying inks. The best method to dry the garment is using a heat press. This will quickly ensure the print area is dry and ready to print, and the pressure of the heat press also helps to ensure that the pretreatment bonds well to the fabric’s fibers.

Mount the Garment onto a Platen

OmniPrint Standard Adult Platen

DTG printers utilize a platen to hold the garment in place as the print head jets ink onto it. The garment is carefully mounted onto the platen to ensure that a perfectly flat surface presented to the print head, properly aligned so that the image is printed exactly where it is expected to be.

Now that the image is loaded and ripped, and the garment is pretreated and mounted, it’s time to print. The print will be initiated from the DTG Rip/Print software, once the printer is properly prepared to print. Preparing the printer to print includes any required preliminary setup steps (depending on your printer model) such as cleaning the print head, setting the platen height, etc.

Cure the Ink

Once the printer finishes printing, the ink will be wet. It’s necessary to cure the ink on the garment. Curing the ink properly is very important for achieving good washability, meaning that the image will remain vibrant after many laundry cycles. The curing process requires that the ink reach a specific temperature and that it be maintained for a designated period of time. For example, we would cure a black cotton shirt at 320-degrees Fahrenheit for 180 seconds.

DTG vs. Screen Printing

Screen Printing

“The technique of creating a picture or pattern by forcing ink or metal onto a surface through a screen of fine material.”

Oxford Languages

Traditional screen printing is a printing method where ink is pushed through woven screen stencils onto fabric. The ink doesn’t soak into the fabric but lays on top of the fabric.

To transfer the ink, a special screen is made for each color in the design. Then, the inks are mixed for each color in the design. Each color is printed onto the garment, one by one, through the screen stencil prepared for that color in the design. The more colors in the design, the more screens must be prepared and the more instances of applying the ink for each color. Once those screens are created and inks mixed for each color in the design, it’s easy to produce a large volume of prints in a timely manner.

The best designs for screen printing are solid graphics without small detail — designs with simple symbols, geometric shapes, and basic typography. This is because making screen stencils for detailed graphics with many colors is very time-consuming and it’s difficult to get fine details right. Screen printers often need to limit the amount of color in a design to reduce set-up time and costs.

Direct to Garment (DTG)

DTG printing is a process of printing graphics onto textiles and garments using an inkjet print head. DTG printers utilize a platen to hold the garment in place as the print head jets ink onto the textile.

Typically, the textile is pretreated with a special adhesive that sticks to the garment’s fibers and allows the ink to bond to those fibers. The chemical composition of this adhesive pretreatment material also causes the “underbase” layer of white ink (which is used like a painter’s base coat of primer when printing on colored shirts) to quickly gel. This prevents the CMYK inks from blending with the white underbase and provides great color vibrancy.

DTG can print just about any type of graphic. All you need to do is load an image into the printer’s software, select a few settings, and click print. Any type of design can be printed, even those with complex graphics and thousands of colors.

Because there are no screens to prepare, DTG has a considerable setup time advantage over screen printing. Depending on the fabric and graphic, DTG may take more time for the actual print. But, since setup is very minimal, DTG enables on-demand order fulfillment with no upfront costs, making one-time and lower quantity print runs economical.

Both screen printing and DTG produce quality prints, but with differing setup methods and costs. Here’s a chart detailing advantages and disadvantages:

DTG
Printing
Screen
Printing
High-quality printsYesYes
Detailed designsYesNo
Unlimited color optionsYesNo
Order minimumsNoYes
On-demand fulfillmentYesNo
Bulk discountsYesYes
Significant setup costs per designNoYes
SustainableYesNo

Choosing the Right Garment

Stack of colorful folded fabrics

When choosing a garment for DTG printing the most important factor will be the quality of your garment. High-quality garments will produce high-quality results, while low-quality garments will produce poor results. And since OmniPrint’s DTG ink is water-based, certain fabrics interact better with the pretreatment, ink, and fabric.

We recommend experimenting with various fabrics by a variety of manufacturers to see which garments work well with your graphics. Typically, DTG printing works best on natural fabrics and natural-synthetic blends. It will take practice to find the right pretreat amount based on the fabric type, fiber content, and amount of pretreat. Here are some general guidelines to consider:

  • Garments with loose weaving may allow pretreatment to migrate away from the top of the fabric, resulting in spotty prints and poor washability
  • Cheaper than average garments should be a warning of low quality
  • Rayon or spandex dominant blends tend to scorch when curing the ink so should be avoided
  • Avoid Carded Open End and garments with too many stray fibers
  • Combed Ringspun 100% Cotton is the preferred garment choice
  • The 330TX model can print on up to 50% polyester
  • The 330TX PLUS model can print on 100% polyester

Once you have considered and optimized these factors you can print on:

  • Beach towels
  • Canvas tote bags
  • Hoodies
  • Crew neck t-shirts
  • Polos
  • Toddler shirts or onesies
  • Jeans
  • Hats
  • Etc…

Climate Control Requirements

It is important to maintain a temperature range of 60° to 80° Fahrenheit and a Relative Humidity range of 45% to 65% to avoid negatively impacting:

  • Print quality
  • Proper consistency of ink and pretreatment
  • Shelf life of ink and pretreatment
  • Service life of print head
Temperature and Humidity

How does the environment impact print quality?

If the humidity is too high, fabrics can absorb and retain moisture, causing ink to bleed. We recommend doing a final heat press on any garment that was previously pretreated to steam out any moisture and remove any wrinkles.

How does the environment impact ink and pretreatment?

The shelf life of our inks and pretreat material is normally one year, but temperatures exceeding 80° Fahrenheit can cause the consistency of inks and pretreatment to permanently change, whether in the equipment or still in their original containers. If this happens the nozzles of the print head or pretreat device may clog, so the material should be replaced to avoid damaging your equipment.

How does the environment impact the service life of the print head?

If the humidity is too low atomized ink can dry on the print head plate and cause clogging. Also, if temperatures exceed 80° Fahrenheit the consistency of the ink can permanently change and result in clogging print head nozzles, potentially requiring that the print head be replaced.

Clogging of the print head due to temperatures or relative humidity outside of the recommended ranges is not covered by your printer’s warranty.

What is DTG?

DTG stands for Direct-to-Garment. It is also called Digital Garment or Inkjet to Garment printing. DTG printing is a process of printing graphics onto textiles and garments. It uses modified inkjet technology to print any type of graphic onto t-shirts, hats, bags, masks, pants, jeans and even shoes. DTG printers utilize a platen to hold the garment in place as the print head jets ink onto the textile. 

OmniPrint International’s Adult Platen

Typically, the textile is pretreated with a special adhesive that sticks to the garment’s fibers and allows the ink to bond to those fibers. The chemical composition of this adhesive pretreatment material also causes the “underbase” layer of white ink (which is used like a painter’s base coat of primer when printing on colored shirts) to quickly gel. This prevents the CMYK inks from blending with the white underbase and provides great color vibrancy.

The result of this ink infusion is a much more natural feel in comparison to other printing or iron-on transfer techniques.

Direct to Garment printing is very precise and ideal for full color and detailed designs. The process gives you nearly endless color possibilities and can make small details pop. Plus, it’s easy to set up and print any graphic. You simply place your garment on the platen, load the image, and hit print.

Unlike screen printing, there are no screens to prepare or change throughout the process. This makes DTG very cost-effective for one-time or small print jobs, and DTG printing scales well for larger print jobs as well.