How to detect and avoid five common sublimation problems.
January 03, 2012
Any form of decoration comes with its challenges; it’s simply a natural part of the learning process. You didn’t jump into the driver’s seat of a car and instantly start driving. The process required training, time, patience and probably included a lot of close calls before you became proficient behind the wheel. The same can be said about decoration production. You learn with experience, but thankfully, the challenges aren’t nearly as difficult as learning how to drive a car.
In the case of sublimation, there are five common problems you probably will encounter along the road to success. Each can be avoided with the right understanding and approach, but inevitably you will most likely end up meeting each problem face-to-face at some point. They say you learn far more from your mistakes than your successes. If that is true, then I must be a genius because I think I have made just about every possible mistake.
For sublimation, the five most common problems are:
• Moisture issues (displaced ink)
• Ghosting and gassing out
• Incorrect output colors
• Transfer lines (on soft goods)
If you encounter lines of missing ink in your printouts, then you likely are having banding issues, the most common cause of which is clogged print head nozzles. Like it or not, all ink — not just sublimation ink — dries over time. If this happens inside the print heads, ink flow is inhibited, which results in streaks of missing ink on the printout. Welcome to banding.
As long as you are printing on a regular basis — at least several times per week — ink will not have an opportunity to dry inside the print heads. But if you experience long stretches of time with no printer activity, you could have issues.
The simplest way to deal with this is to routinely run a small quantity of ink through the print heads by using the head cleaning function of your printer. For Ricoh printers, this is done automatically as long as you leave the printer powered up. However, for Epson printers, you need to perform a manual head cleaning every few days, which can be done with the push of a button.
If you need reminders of when to clean, some software programs are available that will prompt your printer to perform a head cleaning at specified intervals. You set it up and it does the work as long as you leave everything powered up.
Banding has some additional causes other than just clogged heads, such as running out of ink. Before you start going crazy with troubleshooting, make sure your printer has plenty of ink in its system. In addition, your printer may simply need some adjustments in the print head and/or paper feed systems.
The introduction of moisture into the sublimation process can cause unwanted results. During production with a heat press operating at 400°F, moisture can flash to steam and literally blow the ink away from its intended target. Some of the problems that are attributed to moisture include color shifting (colors lose accuracy), image bleeding and the uneven transfer of solid-filled areas.
Under normal circumstances, a small amount of moisture can accumulate in the transfer paper and it’s usually absorbed directly into the substrate during pressing. However, hard substrates like metal and ceramic are unable to absorb excess moisture. Thus, it’s important that you take steps to minimize the introduction of moisture into the process.
The first step is to protect the paper from moisture absorption. As a preventative measure, store your paper in dry place. Consider a sealed container such as a re-sealable bag. If you suspect moisture, set the paper on your press for a few seconds. Do not press it; just expose it to the warmth. The heat radiating from the press should help evaporate most of the moisture.
Another trick is to use newsprint or butcher paper instead of a Teflon sheet. The paper will help absorb moisture from the transfer sheet during pressing, whereas Teflon will not. Be sure to use a fresh sheet of paper for each pressing cycle.
If you are working with garments or fabric, it’s also possible that the substrate may contain a bit of moisture. Pre-pressing the garment for about 10 seconds should remove the moisture, as well as any wrinkles.
In addition, you should focus on your work environment. High humidity levels usually contribute to moisture issues. A dehumidifier can help control these issues, but reducing it too much can have negative effects on the inks and your equipment. It’s wise to invest in a hygrometer and take some readings. The ideal operating conditions for sublimation are 70°F to 80°F with 35% to 65% relative humidity (no condensation).
Ghosting & Gassing Out
Sublimation requires a tight marriage between the transfer paper and the blank product during pressing. If the paper shifts or is not firmly planted against the substrate, the result will be ghosting and/or gassing out.
Ghosting results in a blurry image, typically characterized by a shadow effect along or outside of the edges. Gassing out is the term used for a “burst” of ink outside of the image area.
To avoid these problems, it is crucial to have a tight fit between the transfer paper and the substrate. I recommend using heat-resistant tape to secure the transfer to the product. Be careful not to tape across the image area, as this can damage the image quality. In addition, use only a minimal amount of tape, since you will need to easily and quickly remove the transfer after pressing.
When sublimating apparel, you can use repositionable spray adhesive instead of tape. Apply a very light mist on the image side of the transfer paper from about 10 inches away. Do not spray the shirt. Next, press the transfer paper to the product. If you position it incorrectly, you can lift it off and reposition it.
Regardless of how you adhere the transfer paper to the product, it’s important that when you remove it, it doesn’t slide along the surface of the substrate. This may spread sublimation dye into unwanted areas and cause ghosting. Ideally, with hard substrates, the transfer will be lifted off the surface quickly and cleanly. With apparel, you may get better results by grabbing one end of the paper and pulling it away slowly, while firmly holding the garment down.
Dirty or stained Teflon blowout sheets also can cause ghosting. This is another reason that you may want to consider using newsprint or butcher paper instead of Teflon.
Incorrect Output Colors
Here’s a rule of thumb: Output color is correct, it’s the input color that’s wrong.
The problem of color mismatch is not the result of a defective system. Rather, it comes from the fact that there are multiple pieces of image-rendering equipment involved in the process, each having different methods and ranges of color management.
First, the computer monitor displays in RGB mode, while the printer is printing in CMYK mode. With sublimation, what comes out of the printer is not the final color, as it will shift again during the pressing. It’s kind of like translating French to English to Spanish. You can get the general message across, but rarely is there a word-to-word match-up. The key is to correlate or match the color on the screen to the color that ends up on the finished substrate.
If you have purchased a sublimation system that includes a printer driver, the software helps to manage the printing functions with regard to sublimation. In addition, if you are using CorelDRAW or Adobe Photoshop in conjunction with your system, you should have installed the manufacturer’s designated color palette into your graphics program. Only use that palette when making color choices, as it will ensure a much better correlation between the screen image and the final image.
In addition to loading your palette into the graphics program, you also should create reference charts that correlate the final production colors to what you see on the screen. To do this, simply print the color palette that is used by your sublimation printer driver (it includes the RGB codes). Then press it onto a reference substrate, such as a coated metal panel. This becomes a visual representation of what the colors will look like in their final form.
Select your design’s colors based on this chart (output) rather than relying on the screen colors (input). It may not look correct on the screen, but you will know what it will look like when it comes off the press.
Transfer Lines on Apparel
Transfer lines appear as faint lines in the fabric that correspond to where the edges of the transfer sheet were located during pressing. They are caused by the shirt fibers melting along the edges of the transfer sheet. If you are an embroiderer, transfer lines look kind of like hoop marks, except they are permanent.
Your first option for preventing transfer lines on apparel is to experiment with your heat press settings. Consider reducing the temperature to 390˚F and reducing the pressure to a very light setting. You also may cut back the pressing time from 60 seconds to about 45 seconds. Changes should be made gradually, as too much variance from the standard settings could affect image quality.
Another simple option is to tear away the excess transfer paper that is not coated with sublimation dye. This will soften the paper’s edges and greatly reduce the potential occurrence of transfer lines.
Many sublimators use a process that incorporates a sheet of high-temperature foam during production to prevent lines from forming. Vapor Apparel produces a turnkey kit complete with instructions and a YouTube video to explain the process. It can be purchased from any of the company’s distributors. Teflon pillows also have been developed for apparel sublimation. Check with your equipment suppliers for more information.
One important thing to remember with apparel is that different garments may need different settings. Regardless of which approach you use, document your settings for future reference.
These are some of the most common issues encountered by sublimators, and each of them is relatively easy to resolve. If you are still having trouble, contact your equipment supplier. Don’t let production challenges slow you down or intimidate you. Most issues can be resolved over the phone, but first you have to make the call.
Award-winning author and international speaker Jimmy Lamb has more than 20 years of apparel decoration business experience. He currently is the manager of communication for Sawgrass Technologies, Charleston, S.C. For more information or to comment on this article, e-mail Jimmy at firstname.lastname@example.org.
Hear Jimmy speak on sublimation topics at the 2012 Imprinted Sportswear Shows. Individual seminars are just $25 if you pre-register: issshows.com.