Sublimation Issues Made Simple

By Tom Chambers

In my last article, I alluded to a future blog post relating to unacceptable sublimation image quality that was caused by “simple issues”.  Well, here are several simple things that can cause hair pulling moments, sleepless nights, and cost you a lot of money – but are easily checked and corrected.

This is not intended to be an exhaustive list of everything that can happen or go wrong.  It IS however a basic guide to most of the simpler issues that can arise, especially when a user is relatively new to sublimation.

While the list below is written with the Sawgrass Virtuoso series of inkjet sublimation systems in mind, it will apply to many others as well.  It does not, however, specifically address additional issues that can arise with bulk ink systems, aftermarket systems, or generic inks.

Some of the following may seem a bit obvious or even silly, but you’d be surprised at how many times these occur in real life – sometimes even to people who know better.

Issue:  The sublimated image is faint / faded looking / invisible, even though it looks ok on paper.

  • Are you using sublimation paper? Yes, sometimes people will get the idea to save some money and try regular inkjet paper or even copy paper.  Results will vary, but in general you will never achieve good quality results with any paper other than one designed for sublimation.
  • Are you printing on the correct side of the sublimation paper? Most sublimation paper has a printable, coated side which is typically a brighter, whiter color, and a non-printable side that is off white, duller, or even watermarked.  Depending on your printer and its printing path, the paper could need placing either face up or face down.
  • Are you using sublimation ink? Believe it or not, this happens.  Simply put, sublimation requires specific sublimation ink designed for the printer that you are using.  Regular ink will not work.
  • Is your heat press on / fully heated up / actually at the displayed temperature? Always give your press time to warm up to the correct temperature first, and you should also be using a pyrometer to keep tabs on the actual vs. displayed temperature.  Read this article for more in-depth information on that subject.

Issue:  The images printed on paper don’t look like what is on the computer screen.

As long as there are no defects showing in the print, this is usually not a problem.  It is normal for the printed image to look duller, darker, or even have different colors from the image on the screen.  Unlike printing a photo onto regular photo paper for example, during the sublimation process the color also changes and becomes more like what you see on your monitor.  The best thing to do is to sublimate the image first, then compare.  If you have doubts, use a piece of polyester fabric to test on first.

Issue:  The sublimated image has a double image / faint outline or shadow, but the printed image is fine.

This is called “ghosting” and is caused when the paper shifts sideways during sublimation while everything is hot.   Most often, it happens when the press head comes up too fast creating a vacuum that sucks in air, causing the paper to move.  It can also happen when you are removing the paper if you pull it sideways instead of quickly pulling it straight up.  Another possibility is on a draw press, when drawing the platen out too fast.  Be a bit more careful, use heat tape to affix the paper to your sublimation blank, use a tiny amount of a temporary spray adhesive on the paper, or use an adhesive type sublimation paper.

Issue:  The printed image and / or sublimated image has light or dark horizontal lines in it.

Light lines are most often caused by one or more clogged print nozzles, where there is no ink being printed of a particular color.  The first thing you should do is print a nozzle check, and look for any gaps in the lines.  You may see only one, or it could be several.  If you do, run a head cleaning, followed by another nozzle check.  You should see fewer or no gaps.  If there are still gaps, repeat the process and check again.  As long as the number of gaps decrease or change locations, continue this process around 5 times, and by then you shouldn’t have any gaps remaining.  If some gaps remain and are always in the same place after a few cleanings, you may have more serious issues that require a call to tech support.

Dark lines are usually caused by the print head being out of alignment, and to a lesser extent, light lines can point to this as well.  To correct this, follow the procedures for your printer to print and adjust the print head alignment.  This is typically a straightforward process that gives you step by step instructions to follow.

Both nozzle check and print head alignment procedures are usually accessed in your printer driver maintenance area.

Issue:  The sublimated colors don’t closely match what it shows on the screen.

This one is a bit trickier to explain as there are a variety of possible causes and troubleshooting is considerably more involved, and there will always be some slight differences between what you see and what you sublimate, but I will address the most common, easiest to fix issues here.  Where more specific instructions are needed, always refer to the information provided with your particular printer and sublimation system.

  • Are you printing to the correct printer driver? With many printers that use Sawgrass ink, there are two printer drivers for your printer – a virtual printer driver that does the color correction for sublimation, and the actual OEM printer driver for printing.  Frequently, I see cases where the OEM printer driver has been incorrectly set as the default, so the color correction is being bypassed.  Always make sure you are printing to the virtual printer driver instead.
  • Are your printer driver settings correct? A very common issue that is easy to overlook is the settings within your printer driver.  If you’ve customized it for a particular product, and then go to print something else, you may receive surprising results.
  • Are you using the correct color management settings in your graphics software? Another common issue is not following the correct procedure for a particular sublimation system when configuring graphics software.  Be sure to read any instructions about color management settings for your system, graphics software version, and operating system.  Failing to set up your graphics program properly for sublimation can cause unpredictable results with color, since you essentially wind up with multiple programs fighting for control of the color output.
  • Are you using the correct color profile? If color profiles are a part of your system, they must be set up specifically as recommended by whoever provided the profile.  Color profiles are a complex topic outside the scope of this basic article, but suffice it to say that not having them set up correctly or using the wrong one will definitely affect your color output.

If the above doesn’t solve your issue, or if you have questions about anything, feel free to contact us.  We’re always here to help.

Tom Chambers is EnMart’s sublimation guru,  the guide and mentor regarding all things sublimation.   Tom was instrumental in introducing inkjet sublimation to industrial laundries, and has been working with the process since the early days of thermal ribbon sublimation. 

If You Own a Heat Press, You Should Own a Pyrometer

By Tom Chambers

What is a “pyrometer”?

In my last blog post  I mentioned using a pyrometer to verify the displayed temperature of your heat press.  In this article, I want to expand on this device and how to use it, and why I think it is the single most underrated yet vitally important tool you can have in your shop.

Simply put, a pyrometer is a device to accurately measure temperature.  In the context of heat presses, and with the addition of a surface probe, it allows you to verify that your heat press is actually at the temperature you think it is.

If you’re thinking “yeah, right, it probably costs a lot…”  No, it really doesn’t.  And what it does cost, it can save you, the first time you need it.

Why buy a pyrometer?

I’ve lost count of the number of phone calls I’ve received regarding sublimation image quality.  While most of these could be traced to simple issues (more on those in a future post), there have been a handful that were directly related to the heat press the customer was using.  In almost all of those cases, if the customer simply had an inexpensive pyrometer, they could have saved themselves days of aggravation, phone calls, ruined products, and a significant amount of time and money.

Here’s the thing – unless you are very lucky, or the press was calibrated precisely in the factory, the temperature it shows on the display, dial, or gauge is not what the actual temperature is.  As a press ages, that variance will also change.  Digital gauges are the most accurate, but they still have to be calibrated periodically.  Dials or gauges that insert into the platen are notoriously inaccurate.

Ultimately it boils down to one main fact – if you don’t have an accurate method of double-checking your press temperature and you have any issues with the products you are pressing,  you simply cannot determine whether the problem is with your heat press or the product itself.

What kind of pyrometer should you get?

There are two popular types of pyrometers.  You may have even seen the first type, a hand held gun-like device using an infra-red sensor, typically with a laser pointer built in.  Some people think that the laser is the sensor, but it isn’t – it’s only there as a pointer (or to play with your cats).

Those are usually the least expensive, but the problem is that they only work well on things that have no reflectivity, like walls, carpet, ceilings, or dark/matte surfaces.  Since many heat press platens are aluminum (which is somewhat reflective), it will give you a false reading.  Even if you have a coated platen with a dark matte surface that it will work with, it won’t always remain so, and will develop blemishes over time that will alter the readings.

The second type, which is what I recommend, is a hand held unit that looks much like a multi-meter, with the addition of a plug-in surface probe.  In this case, you place the end of the probe against the surface of the heat platen for a few seconds to obtain a direct reading of the temperature.  Because the temperature is measured with a sensitive probe and direct contact with the platen, any color, reflectivity, or blemishes simply don’t matter.

What’s the best way to use a pyrometer?

Heat up your press to whatever operating temperature you need, including setting the pressure and timer.  Draw a tic-tac-toe grid on a piece of paper, and use the surface probe to measure 9 spots on the platen in the same tic-tac-toe pattern.  Hold the probe against the platen several seconds, until the temperature on the display stabilizes.  Write those temperatures down in the corresponding squares of the grid you drew.

Now, run a complete pressing cycle as if you were producing the product of your choice.  As soon as it is finished, take a new set of 9 temperature readings and record those below the first set of numbers.

The difference between the first and second numbers will give you the likely drop in the press temperature during operation, and the differences between the 9 different locations on the platen will point out any hot or cold spots.  You’ll also be able to instantly see if your press has a problem.  Any significant variances (more than 20 degrees F) between the highest and lowest numbers can be a problem, depending on the tolerance the products you are pressing allows.

To set the press to provide your ideal temperature, average the first set of numbers together, then average the second set.  Pick a temp between the two averages, but closer to the higher number.  That should match the temperature recommended for the product you are pressing.  If it does not, then adjust your press so that it does.  You may have to repeat the measurement process above a few times to get it dialed in just right, but once you do it, you should only have to check it periodically.

If your press has a feature that allows it, once you dial in the temp, you can calibrate the temperature display to show that exact temperature.

What’s the purpose of all that?

No press is going to maintain the exact set temperature 100% of the time, since heat energy leaves the platen and goes into your product when you are pressing it, and the press then has to switch on and heat the platen back up.

By using your pyrometer, in addition to knowing exactly what temperature your press is, you are able to set any good quality heat press to compensate for those swings in temperature, and even minimize the variance on less expensive presses.  You also have the added benefit of diagnosing any problems that may be occurring related to heat.

Different manufacturers of presses handle the temperature in different ways, and some of those methods can cause delays between when the platen reaches its set temperature, and when the press turns off the heat, resulting in over-shooting the temperature.  The same thing can also occur on the low end before the press turns back on.  This and other reasons cause variances in temperature.

Good quality presses minimize this variance with various technologies that allow for continuous press operation and even heating, whereas lower quality inexpensive presses are typically made to meet a low price point and usually have temperature swings that can be wide enough to cause you to have to wait between pressings for the temperature to recover along with cold spots in the platen.

This will ultimately improve the quality of your products and save you time and money if you ever have an issue with your heat press, because it will let you pinpoint whether the problem is related to the temperature of the press or not.  Even if the problem isn’t the press – you’ve now eliminated it as an issue, which is something you can tell your product tech support when calling to explain that you aren’t getting the results you should be.  That will save you both some time, helping you get back up and running again quickly.

Tom Chambers is EnMart’s sublimation guru,  the guide and mentor regarding all things sublimation.   Tom was instrumental in introducing inkjet sublimation to industrial laundries, and has been working with the process since the early days of thermal ribbon sublimation.