Tag Archives: pretreatment
DTG printing can produce some pretty incredible full-color prints, but one thing that can really ruin the overall appearance of any print (no matter how vibrant or beautiful the image may be) is fibrillation – those annoying little fibers that always seem to pop up through the ink, causing an otherwise great looking print to look rough or patchy. No matter what ink / pre-treatment combination you use or which DTG printer you print with, the problem exists across the board. Of course, selecting the proper garments for DTG printing can go a long way to help reduce this problem (look for garments with a smoother print surface; blanks that have been treated with an enzyme wash are a great place to start) but there are additional steps you can take to help reduce this problem – brushing the shirt after pre-treating is perhaps one of the easiest and most effective of these, and choosing the proper tool is vital.
The purpose of brushing the garments is two-fold:
- Better Pretreat Coverage: By brushing the entire printable area after spraying, you spread the pretreat fluid around and ensure more consistent penetration.
- Push Down Garment Fibers: By applying consistent pressure while brushing in smooth, consistent strokes, the fibers of the garments are pushed down creating a smoother, more even print surface.
When we started printing white ink with DTG, we evaluated a wide variety of foam brushes, rollers, etc – although these worked modestly well for spreading the pretreat fluid evenly across the print area, our experience showed us that the porous foam brushes seem to pull the fibers up more than they push them down, thus negating the effect and doing little to prevent fibrillation.
At some point it was recommended to us to try using premium Wooster brand brushes instead of foam rollers / brushes, so we invested a few bucks in a (6) pack of 4″ wide brushes and we haven’t looked back since. These brushes are perfect for use after spraying the pretreat fluid on the garment, and they do a much better job of pressing the fibers down onto the garment (without lifting them back up in the process). We strongly recommend giving these brushes a try if you are involved in DTG printing, especially if you are experiencing trouble with fibrillation in the final printed garment.
The specific brushes we use are available online at the following website: Buy Wooster Brushes Online!
When using DTG printing as a decoration method, there are many additional steps that are not necessarily required for traditional decoration methods (such as screen printing). For example, many people are not aware that we must spray a liquid “pretreatment” chemical on all dark garments before they can be printed using the DTG process; this additional step is required to ensure that the white ink that is printed onto the garment does not “soak in”, literally disappearing before your very eyes.
In addition to the requirement that we must currently pretreat all dark garments, we are often asked to pretreat light garments as well (the improved color vibrancy and washability on light garments is worth the extra cost) – once again, the pretreatment liquid acts as a “barrier” to prevent the CMYK inks from soaking into the garment. Without this pretreatment on light garments, the print would appear slightly more faded, although still acceptable (whereas dark garments literally cannot be printed without the pretreatment step).
During the curing process, the pretreatment can discolor slightly, and can sometimes leave a slightly off-white residue that may be interpreted as a stain of some sort. This is entirely normal and should disappear with the first wash of the garment. If you want to test it out, try wetting a clean cloth and gently wiping around the edges; you should notice that the effect is minimized, which should offer some reassurance that the first wash will indeed take care of the phenomenon. When pretreatment is applied to certain light garments, the curing process will sometimes cause a light “yellowish” box to appear around the design – again, this is most often caused by normal discoloration of the pretreatment fluid on the garment, which should come off in the first wash. The pretreatment residue is completely harmless (just don’t try to eat your shirt and you should be fine) and is used by any person who is using a DTG printing system; unfortunately it is simply a fact of the industry at this point.
Aside from the possible discoloration of the pretreatment fluid itself, you may also notice a “box” around the printed design – this box is can sometimes be caused by the pressure from the heat press (used for curing the inks) forcing the fibers down into the garment. Since we are applying high heat and heavy pressure for an extended period of time, this box will sometimes be noticeable until the garment goes through the first wash cycle. Additionally, thicker items such as fleece, and items that contain polyester will usually have a harder time masking the difference between the area that has been heat pressed and the area that has not; once again, the first wash should take it back to normal.
Some garments will show an enhanced version of this effect, while other garments will show no signs of the pretreatment area at all – at our sister company (www.fusionlogisticsgroup.com) we try to encourage all of our clients to select garments based on the following criteria:
- How well they print
- How well they wash after curing
- How well they accept the pretreatment fluid
DTG Print Solutions is pleased to have been given the opportunity to become an early BETA tester for the ViperONE automatic pretreatment machine, which is being delivered to the market by i-Group Technologies, LLC (the same team that brought out the original Viper automatic pretreatment machine). For many years, our sister company Fusion Logistics Group has gotten by with the traditional Wagner HPLV sprayer for manual pre-treatment application – the results were not always perfect, but the process has become far more forgiving and manageable in recent years. Printing thousands upon thousands of shirts has made our staff incredibly knowledgeable regarding the manual application of pre-treatment, and we have come to accept this as a normal part of the DTG printing process. Although we have indeed tested other automatic pre-preatment machines in the past (including one which sat dormant in our shop for over a year before we got rid of it), none have ever delivered upon our expectations of reliability, consistency and quality. That all may have changed, however, with the introduction of the new ViperONE pre-treatment unit.
Our staff was eagerly anticipating the arrival of the new ViperONE pre-treatment machine, long before it actually arrived – since we got our hands on a very early concept model, we had to be patient while the necessary adjustments were made by the manufacturers; we were kept informed during the entire process, and when our delivery date came it was like an early Christmas. At some point in the mid-afternoon, I received a call from my production manager to inform me that the pre-treatment machine had arrived – he asked me what I thought we should do with it, and my response was “Well if you feel so inclined, feel free to set it up and take a look at it – otherwise I will be in the shop in a few hours”… Imagine my surprise when the response from the other end of the phone was “Phew, thank goodness – I already unpacked it 20 minutes ago and have been pre-treating shirts with it!”
This anecdote speaks to the ease at which my staff was able to unload the unit (which, by the way, is incredibly compact), set it up and begin implementing it into our production process; although they were in the early evaluation stages, they had no trouble getting it ready to go with almost no direct guidance or instruction. Ease of use is an incredibly crucial factor these days, especially if you plan to utilize paid employees to do your bidding while you’re in Vegas blowing all your earnings on Blackjack…
As mentioned, the unit is physically compact and occupies a much smaller space than the original Viper pre-treatment machine. This makes it easy to integrate into a small production area, where space is a valuable commodity. Our initial feeling was that there could have been a little more money put into some of the construction materials used to build the unit – in particular, we felt the slide rails were not as sturdy as we were used to seeing on other equipment. We discussed our feedback with the manufacturer, but the feeling seems to be that any improvements in this area would add quite a bit to the manufacturing costs – since we do not build or source the parts, we will have to take their word on that!
The machine utilizes a drawer-style design which involves the main body of the unit (where the actual drawer is), an upper spray mechanism and an assortment of tanks / bottles to dispense and recollect the pre-treatment spray; the machine also requires a small air compressor unit to operate (not included), which is a departure from the original Viper design (which utilized electronically controlled spray nozzles, rather than pressure nozzles). To be completely honest, we were unsure how well the single-nozzle design would work out, considering we have never seen a single-nozzle unit that performed to our specifications – now that we have had some time to fully evaluate the system, we are pleased with the consistent and smooth results we have been able to achieve thus far. Although we notice that the outside edges seem to vary from the center of the spray area, slightly, our experience has shown that this subtle discrepancy has almost no effect on the quality of the prints we are getting on our Neoflex printers. The improved quality and repeat-ability we are able to achieve now in our pre-treatment department has surpassed even our most optimistic expectations, and our printing business has been positively impacted by this change – any slight difference in spray volume seems unnoticeable in the printed image, as the improved quality we are now getting far outweighs any concerns we may have had.
EASE OF USE
Our employees had little difficulty setting up the machine and pre-treating the first couple of shirts – in addition, Brian Walker was kind enough to provide some thorough documentation, including a user guide that helped indicate how much fluid should be applied to get the best results. When dialing in the machine, there is a knob which you turn either direction to increase or decrease the amount of air flow, thereby affecting the volume of pre-treatment that is ultimately applied; we found that it can be a little tricky to determine the “zero point” for the dial, due to the fact there is no hard-stop when turning the dial counterclockwise. A trick we were shown is to rotate the dial until we felt resistance, at which point it was at the “zero point” – from there, each full rotation would increase the spray volume incrementally. This process is fairly simple, although it does not eliminate the need for someone who truly understands the pre-treatment process to be available during production, in case something needs to be dialed in again – since most brands / styles / colors require varying levels of pre-treatment to be applied, the machine would need to be re-adjusted on a fairly frequent basis.
Once the machine is dialed in for a particular garment style or color, it becomes a simple process to just load the shirt, close the drawer and press the “GO” button – in fact, you could almost hire anyone to perform this step over and over again, as long as the person who was actually dialing in the machine knew what they were doing (I would not leave that step to just any random employee, since it will ultimately determine the quality of the prints you will be getting). Before I had even arrived at the shop to inspect the unit, my production manager had already set up the machine, dialed it in and had several employees pretreat some shirts to test it out – the only issue that came up involved one particular employee holding the green “GO” button for an extended period of time, which apparently causes the spray nozzle to get stuck in the back position with the spray coming out full steam ahead… The solution, I am told, is to make sure your employees do not hold the green “GO” button for an extended period of time! Makes sense to me, and we have not had that issue since we became aware of it.
The price range of the ViperONE pre-treatment machine is projected to fall between $3,500-$4,000 – while this may seem rather steep for a secondary piece of equipment, many shops will find the added consistency and quality to be well worth the investment. After thoroughly discussing the price issue with my production manager, we are in agreement that although it seems expensive when you look at the fundamental construction of the machine, the value that it provides our business far exceeds that number and it is well worth the investment, regardless of the build cost – this is an example of a product being worth “well more than the sum total of it’s parts”. As many people who are running their own DTG print shops will tell you, the stress and frustration (not to mention wasted prints and resources) of the manual pre-treatment process, while completely manageable if you put your mind to it and monitor the process closely, is one of the biggest hurdles that stands between them and long term success; if you could remove the headache and stress that this step causes, and ensure that a full run of 100+ dark garments will print the same from the first to the last garment, would that be worth the price tag to your business? For us, the answer is yes.
An automatic pre-treatment machine is not the first thing a startup DTG print shop should be looking into – before you begin to automate this process, you should become an expert by manually applying pre-treatment to hundreds if not thousands of shirts. Without this thorough and fundamental understanding of the way pre-treatment works and what affects the ultimate quality of the print, you will always struggle to make the process work effectively. Additionally, if you are only printing a few dark garments per day, the time and effort involved with setting up the machine and subsequently flushing it out when you are done is simply not worth it; due to the nature of the pre-treatment chemicals used by most DTG ink manufacturers, it is not recommended that you leave anything sitting in the machine overnight.
If you are printing 30+ dark garments per day and feel that you have a decent understanding of the pre-treatment process, you might consider adding an automatic pre-treatment machine to your arsenal – the ViperONE has proven to be a great choice and is allowing us greater confidence in our process from start to finish. Each garment is loaded onto the “platen” and the drawer is manually closed – once you are ready to spray, you simply press the green “GO” button and the nozzle travels across the garment to apply the pre-treatment; the entire process only takes a few seconds, so it is easy to pre-treat 60 shirts per hour without breaking a sweat. If someone were to really hustle on the machine, I wouldn’t be surprised to see 120+ shirts per hour being pre-treated with little difficulty.
Rather than spraying the shirt once, we have found that we get better fluid deposit on the garment when we lower the volume down and press the “GO” button twice, instead of once; we subscribe to the professional painting philosophy that “two light coats are always better than one heavy coat”. By laying down two light passes instead of one, we seem to get smoother pre-treatment results with more consistent fabric penetration – this is especially important when printing on porous cotton (such as standard vs. ring spun), or fleece materials. Additionally, we have not eliminated the “brushing” step that precedes the heat press – after we spray each garment, we quickly brush it down with a high quality Wooster brush, to ensure that fibrillation is minimized.
At the end of the day, we are very happy with the ViperONE automatic pretreater, and our thanks go out to the team at i-Group Technologies, LLC! This device may even allow us to begin offering “pre-pretreated” shirts to some of our local DTG customers, providing them even greater control of their own printing process while they build up the necessary volume to justify the purchase of an automatic machine – we believe the difference in print quality and consistency speaks for itself. As i-Group Technologies, LLC makes this product commercially available, watch for it to appear on one of our product pages for you to purchase for your own DTG print business! Remember, if it doesn’t work for us in our own production facility (www.fusionlogisticsgroup.com), we won’t recommend it!