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