DAGuide

When using a direct-to-garment printer, you are printing ink directly on to a garment or substrate.  This means that you don’t have the benefit of having a transfer paper with a polymer adhesive on it to help with the washfastness of the ink.  So the ink that you use in your dtg printer must have special binders in it to allow the ink to remain vibrant on the shirt after it has been washed.  Although traditional pigment inks are less prone to clogging, they don’t have the washfastness needed to commercially sell garments in most cases.  So you do want to verify that the inks you are using in your dtg printer are designed for printing on to fabrics directly.  In addition, the viscosity of the dtg inks must match the print head in your dtg printer or you can have either ink leaking from the print head or clogs.  There are a couple of different viscosities of dtg ink being sold currently, so please make sure that you verify you have the correct viscosity for your printer.

Should you decide that you want to try a different type of ink in your dtg printer, you are strongly encouraged to flush the ink delivery system using the appropriate type of Cleaning Fluid (ask your manufacturer / distributor for the one to use) and you should consider replacing the ink cartridges / dampers.  There is a strong chance that if you mix two different types of ink in your printer that the two inks will begin to coagulate (i.e. bond together) and clog the ink delivery system.  It is very difficult to remove all the ink from some of the ink cartridges and dampers – thus the recommendation to change these out.  All though these recommendations do take additional time and money, it is well worth it to prevent the ink from clogging in these items and the print head (which is one of the most expensive consumable part to replace).

We hope this document answered the question thoroughly for you.  Feel free to continue a discussion about this question by clicking on the link(s) below.

• http://www.t-shirtforums.com/diy-dtg/t32499-78.html#post394129
• http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t70153.html

The most controversial part to dtg printing is the chemistry involved with the ink and pretreatment.  Over the past couple of years, the advancements in the ink and pretreatment have occurred at a rapid pace.  Additionally, the ink manufacturers are continuing to work on improving the color, maximizing the wash fastness and making it easier to work with the inks. 

dtg inks are transparent in nature like most regular desktop inks, heat transfer inks, sublimation inks and solvent inks.  This means that if you want accurate color reproduction, you will want to print on to a white substrate or background.  Otherwise, the color of the garment or substrate will show through the transparent inks and alter the colors of the graphic or artwork.  The only exception to this is the white ink used by dtg printers.  The white ink contains titanium dioxide (TiO2) particles that reflect light and will allow you to print an opaque white underbase layer on to dark garments or substrates.   TiO2 is a chemical compound that is used in several things like white icing for cakes.  For more weird, but fun information on TiO2, check this link out - http://www.screenprintinguniversity.com/forums/viewtopic.php?t=3926.   For more information as to when you will want to print a white underbase layer, check this link out - http://www.inkjetgarmentprinters.com/forums/viewtopic.php?t=3123.

BUSINESS TIP:  You will want to check with your local government agency to see what rules apply to your business.  One of these rules is most likely to keep Material Safety Data Sheets (MSDS) on hand for all chemicals (i.e. ink, pretreatment,…) used in the shop.  The MSDS sheet will note several key things like any potentially hazardous chemicals, what to do in case the chemical is inhaled or digested, the contact information for the manufacturer and so on.  You can get these MSDS sheets from your distributor or dtg manufacturer.  I recommend you keep the MSDS sheets in a 3-ring binder that is stored in a visible location.  Here is a link to a post on more information about MSDS sheets - http://www.screenprintinguniversity.com/forums/viewtopic.php?t=4336.

What can dtg Inks be Printed On?
If you walk a trade show or go into a show room, you are bound to see non-garment items that have been decorated using a dtg printer.  So, the question of what types of items can I use dtg inks on always comes up and the answer is – it depends on what the item is and what it’s going to be used for.  dtg inks are specifically manufactured to bind with natural fabrics (i.e. cotton, bamboo,…).  However, you can print on to synthetic fabrics (i.e. 50/50, polyester,…) and hard substrates (ceramic tile, wood,…) with some additional steps.  However, knowing what the item is going to be used for will help to determine whether dtg ink is appropriate.  If the item is not going to be cleaned (whether by a washing machine, by hand or by nature – i.e. rain), then there is a higher chance that the ink will remain on it for a limited time.

PRINTING TIP:  Some non-natural fabrics will require you to lay down either pretreatment or an inkjet receptive coating (IRC) before you print on them to prevent the ink from bleeding.  You might also want to adjust the ink density levels as well.

Below are some links to posts that talk about printing on to synthetic fabric and hard substrates using dtg inks:
- Polyester Golf Flags - http://www.screenprintinguniversity.com/forums/viewtopic.php?highlight=flag&t=3420  
   and http://www.screenprintinguniversity.com/forums/viewtopic.php?highlight=flag&t=1795.
-  Ceramic Tiles for Photo Collage - http://www.screenprintinguniversity.com/forums/viewtopic.php?highlight=tile&t=2239.
- Safety Reflective Vests (Not Washable) - http://www.screenprintinguniversity.com/forums/viewtopic.php?highlight=safety+vest&t=4327.
- Polyester Fabric (with no pretreatment) - http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t51220.html
- 65 Poly / 35 Cotton Fabric - http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t33262.html

Just like any other printer, a dtg printer uses either a print driver or a RIP to convert the design into a formatted file that the printer can read.  Most CMYK Only printers will use just a print driver.  However, a CMYK+White Ink printer will have a RIP software to help process the white ink underbase layers.  Both type of software are fine, but in most cases a RIP will provide the operator more control over the colors and ink being printed.

      
Brother GT-541 Driver                                  MultiRIP GP Print-From RIP

BUSINESS TIP:  You will want to pay close attention to the software for all the dtg printers you are considering as there are very simple ones and there are complex ones.  Depending on the operator’s graphic software experience and willingness to learn, you will want to choose the software that works best for your business.

 All direct-to-garment printers include software to drive it.  Some of these software packages can only open raster files (JPG, PSD, TIFF, etc.) and thus are simply “Printing Utilities” and not truly a RIP.   A print driver is similar to the basic software you would get with your standard desktop printer.  You will find some simple selections (i.e. draft, enhanced, photo,…) to choose from that will allow you to adjust your print settings.  An example of a dtg printer that uses a print driver is the Brother GT-541.  For a software package to be a true RIP, it must be able to rasterize page description languages like PostScript or PDF.  If it only handles raster files, it is a “printing utility”, not a RIP. You might be asking… So?  Well, the answer is two words: Print Quality.  When you have a professional rasterizer (a true RIP), you’ll get better output, smoother blends, better font reproduction, better color matching, better image-size interpolation, etc.

Although a RIP is not as important in a CMYK-only setup, it is indispensable in a CMYK+White ink or dual-CMYK setup.  In general, a RIP software allows you more control over the colors of the graphic used by the printer by allowing for choices like: RGB / CMYK Color Source Profile, Resolution, Uni-Directional vs. Bi-Directional printing, assigning ICC / ICM profiles and more.  RIPs will also help with creating the underbase layer when printing white ink. 

BUSINESS TIP:   If you are a MAC user, confirm with the dtg manufacturer that the print driver or RIP will work in conjunction with your MAC computer in advance.  Otherwise, you will probably want a dedicated Windows computer to drive your dtg printer. 

PRINTING TIP:  When printing on to any type of fabric, you graphic should not be over 200 DPI in resolution as the fabric will not be able to hold a higher resolution.  Printing at a higher resolution most likely is a waste of ink and may cause ink to puddle on the fabric.

There are two types of RIP software programs: print-to RIP and print-from RIP.  The main differences between the RIPs are a print-to RIP will allow you to print directly from a graphic software (i.e. Photoshop, CorelDraw,…) and a print-from RIP requires the graphic software to be loaded into the RIP before printing it.  Examples of dtg printers using a print-to RIP are DTG, Flexi-Jet and Direct Advantage lines of dtg printers. 

 
Flexi-Jet Print To RIP Application

A print-from RIP requires that the design to be saved in the graphic software program and then brought into the print-from RIP application.  Examples of dtg printers using a print-from RIP are the T-Jet and Anajet lines of dtg printers. 

 
T-Jet FastRIP Print-From Application

Some RIP software, like MultiRIP GP, provide the user both a Print-To and Print-From RIP applications.  For more information about MultiRIP GP, please visit www.multirip.com/direct_to_garment.html.

TECH SUPPORT TIP: Make sure that there is adequate information (whether written or videos) on how to use the different features of the RIP.  Very few people are able to fully understand a RIP and its features during a training class.

The platen is the apparatus that is used to secure the garment or imprintable during the printing process.  Over time, there have been five primary types of platens that have been sold as a standard platen for direct-to-garment printers.  There are also other specialty platens that can be purchased as well.

NOTE: Some printers are sold with different platen setups depending on which geographical region you are located in.  Make sure you ask the distributor what type and sizes of platens come with the dtg printer you are considering purchasing and which ones are available as accessories.

Hoop Ring Style: Used by the T-Jet1/2, Direct Advantage, DTG Kiosk and others.  Similar to embroidery, a thin piece of metal or plastic is place around the edge of the platen to secure the garment to the platen.

Clamp Style: Used by the Kornit Printers, Dream Jet and others.  Similar to a hoop ring, the clam is a thin piece of metal that goes around the platen, but is hinged at one side of the platen.
     

Tuck Style:  Used by the T-Jet3, AnaJet and others.  This style platen allows for both sides of the garment (i.e. front and back of the shirt) to be laid on top of the platen.  Then the user will simply tuck the excess amount of the garment under the platen to allow the platen to travel through the printer without the garment getting caught on anything.

Gasket Style: Used by the DTG Kiosk HM-1 and others.  Similar to a tuck platen, both sides of the garment are laid over the top of the platen… but the excess garment material is tucked under the platen and is pushed between two pieces of rubber gasket.  The rubber gaskets will keep the shirt held in place.

Screen Print Style: Used by the Brother printers, Anajet, M&R I-Dot and others.  This style of platen allows the user to load the garment on to the platen like a screen printer.  The user will open the garment up by putting the hands at the bottom of the shirt to allow the sliding one layer of the shirt over the platen and the other layer is below the platen.

Below are some pictures to some of the specialty dtg platens that can be purchased as well.

Brother Mammoth Platen - Stitch City

Brother Cap Platen - Stitch City     Cap Platen - Livingston Systems

Sleeve Platen - M&R

Brother Short Sleeve Platen - Stitch City

Golf Ball Platen - DTG Digital

A dtg printer will use electronic pulses to control either a belt or screw drive to move the platen or printer.  Both options are viable means for moving the necessary item (i.e. the platen or the printer).  If the dtg printer uses a belt drive, make sure that the belt is pre-stretched or has a teflon coating on it minimize any stretching that will typically occur to a belt drive over time. 

 
     Brother GT-541 Belt Drive

If it uses a screw driver, make sure you ask whether there is any maintenance or lubrication need to be done to it.

 
        Flexi-Jet Screw Drive

Whether the dtg printer has the platen move under the print head or the printer moves over a stationary platen, it uses rails to keep the moving part aligned with the stationary part in a similar fashion of how trains run on railroad tracks.  These rails can either be a draw slider type or a solid shaft using a linear bearing system.  A draw slider type rail has channels that the part slides forward and back like a kitchen cabinet drawer. 

 
        T-Jet3 Slide Rails

A solid shaft / linear bearing system transfers the majority of the weight to the bearings and puts less stress on the motor that drives the movable part.

        GT-541 Solid Linear Rails

MAINTENANCE WARNING:  Some dtg printers require you to keep the rails lubricated.  Contact your manufacturer to determine what maintenance, if any, is necessary for the rails.

The ink delivery system is an integral part to any dtg printer.  The ink delivery system is made up of the specially formulate water-based dtg ink, the ink lines and the ink reservoir – whether it is an open ink system (bulk refill system) or a closed ink system (cartridge based system). 

               
   Brother GT-541 Closed Ink System                       T-Jet 3 Open Ink System

Most dtg manufacturers will try to minimize the length and the number of turns the ink will have to travel before it makes it to the print head.  

DTG Kiosk HM-1 Ink Lines 

The ink lines will connect the ink reservoir with either the dampers or print head ink cartridges that are right above the print head.  The primary purposes of the dampers or print head ink cartridges is to make sure the print head always has ink in it and they will filter the larger particles in the ink to protect the print head.

             
                    Ink Dampers                                                              Print Head Ink Cartridges

MAINTENANCE WARNING:  When printing with white ink, make sure that you keep the ink flowing through the machine.  Most dtg manufacturers will have you agitate the ink by shaking the cartridge or bottle periodically.  But the best way to keep the ink flowing in the ink lines or print head is to actually run prints through the printer.  You can either run a print every day or two to keep the ink flowing or you will have to run head cleanings to clear any blocked channels.

When there is a problem with the ink flowing to or through the print head, it is commonly referred to as ink starvation.  Some common solutions to ink starvation are the following:
1.  Maintain the humidity in the room to around 50% at all times
2.  Raise the height of the ink bottles if you have a gravity feed ink system
3.  Clean / replace the capping station and wiper blade extremely well
4.  Clean the bottom of the print head based on manufacturer’s recommendations
5.  Flush / replace the dampers.

The maintenance station (which also contains the capping station) is where the print head is docked when it is not printing and when the printer is performing any maintenance procedures.  The maintenance station is made up of three key items: the wiper blade, the capping station and the evacuation pump. 

The wiper blade is used to wipe the bottom of the print head as it leaves the maintenance station to begin printing.  There are two parts to a wiper blade: the felt side and the rubber side.

The capping station is a rectangular flat sponge / filter surrounded by a raised gasket.  When the print head is in the parked or non-printing position, the gasket presses against the print head - sealing the print head to prevent the nozzles from drying out due to exposure to air. 

   
                  Capping Station                                      Gasket

The capping station is also an integral part of the cleaning procedures the printer will do – either manually controlled by the user or automatically done by the firmware.  The sponge or filter in the capping station is a porous material that is connected to a small evacuation pump.  During a cleaning cycle, ink is pulled or printed out of the print head and drains through the sponge by the evacuation pump into the waste ink tube and out to the waste tank. 

MAINTENANCE WARNING:  Ink build up on wiper blade, gasket or sponge can lead to excess ink getting on the bottom of the print head and transferring to the shirt.  In addition, ink build up on the gaskets or sponge may prevent the print head from making a complete seal during non-printing functions and allow the nozzles to dry out.

The encoder strip is clear plastic strip located behind the Printer Carriage and actually runs behind and thru the Printer Carriage. The encoder strip has little thin vertical lines on it. There is also an electronic eye behind the Printer Carriage that reads the lines and counts them to determine the location of the Printer Carriage on the Carriage Shaft.  The firmware of the printer will use the lines of the encoder strip to coordinate the firing of ink out of the print head to print your graphic.

  
      DTG HM1 Encoder Strip                             Flexi-Jet Encoder Strip

MAINTENANCE WARNING:  Some of the simplest errors and misprints are because the encoder strip is dirty.  Ask the manufacturer for the recommendation on what cleaning chemicals are safe to us when cleaning the encoder strip.

When cleaning the encoder strip on a dtg printer, you will want to use some type of lint-free cloth or wipes so that you don’t leave anything on the encoder strip when you are doing cleaning.  Here is a picture of wipes originially used for cleaning glasses that are recommended by some manufacturers and distributors of direct-to-garment printers.

These cleaners are made with a micro-fiber pads that will not mark the encoder strip and leaves not remaining material like a cotton towel does.  Because there are pads on both sides of this cleaner, you are able to wipe down both sides of the encoder strip at the same time.

The Print Carriage is the housing that contains the Print Head, Ink Cartridges and Dampers (if there are any).  The Print Carriage receives data from the motherboard, makes contact with the ink cartridges and tells the print head when to fire drops of ink out of the nozzles.

 
                Flexi-Jet Print Head                             DTG Kiosk HM1 Print Head

Most dtg printers use a piezo print head to lay down the ink on to the imprintable.  Without going into the technical terms or process, a piezo print head uses electronic pulses to fire ink down on the garment or imprintable.  Although all the print heads do basically the same thing, some of the print heads will have different internal parts – like dampers.  Dampers are small ink reservoirs that have a filter inside them and their primary purpose is to make sure that the print head is always full of ink.  It is important to understand how the print head operates in order to perform technical support when the designs are not printing properly.

MAINTENANCE WARNING:  There are several posts in the forums to how some people have removed clogs in the print head.  I highly recommend that you speak with the manufacturer before trying any of these methods.  The print head is the most expensive consumable part on your printer and you want to be careful when cleaning it.

Some dtg printers will have more than one print head.  If this is the case for your dtg printer, you should also know that there might be more maintenance / technical support issues that will need to be addressed.  You will also want to know what the cost per a replacement print head as well.

 
         Brother GT-541 Print Heads                         Kornit 932 Print Heads

The Decorated Apparel Industry was taken by storm in late 2004 when some of the first commercial based direct-to-garment printers were released. Before you can truly understand why dtg printing has become so popular, you will need to understand some background history. For years, if you wanted to print a couple of cotton shirts you would use either digital transfer paper or try to screen print the order. Both of these decorating methods have their positives, but they also come with negatives.

Digital transfers allow you to create as little as a one-off shirt via a standard desktop inkjet or laser printer. The cost to make a single transfer can range from $0.50 to $2.50 depending on what ink and paper is used by your printer. However, the transfer paper is covered with a polymer (AKA adhesive) that glues the ink to the top of the shirt. The polymer typically will leave a hand where it is applied and can discolor the shirt or create a window around your graphic. New transfer papers have been release that either minimize the window or uses a 2-step process to eliminate the window completely.

Screen printing has traditionally been the decorating method of choice for most of the apparel that you see in retail stores. With screen printing, ink is only dropped down on garment where the design is. Thus, eliminating the undesirable window that can occur with some digital transfer paper. However, a graphic must be separated (the process that breaks the down graphic into the different colors needed to print it), a screen must be burned for each color and it requires a screen printing press to be setup. This can become a very time consuming and expensive process when you only need a few shirts. Commonly referred to as a short run, which can be as low as 1 shirt to as many as 48 depending on the size of the shop, the cost per a screen printed shirt could easily be more than what your customer is willing to pay for.

With the changes in fashion leaning more toward short-run, limited edition personalized garments, the need for a high quality solution grew. Of course, apparel decorators are never satisfied with the concept that things are never going to get any better. Manufacturers and distributors continued to push the boundaries by finding cheaper and faster ways to screen print or to creating better inkjet transfers papers with less hand or feel to them. But the introduction of dtg printing allowed us to take the positive aspects of both inkjet transfers and screen printing in a solution that could be done in a compact space.

The concept of dtg printing is basically using a digital printer to lay down a textile water-based ink that has chemical binders that allow the ink to remain on the garment without a polymer being applied to the top of the shirt like a transfer. The ink is then cured to the garment using either a heat press or a textile conveyor dryer. On average, an apparel decorator can take the artwork from a customer, put it on to a garment and get paid by the customer in under 10 minutes. With some modification to the artwork, the decorator can personalize the next garment with a name, number(s) or different colors and produce another custom garment in minutes. That is the beauty of dtg printing – short run, personalized garments in the matter of minutes.