Humidity and Sublimation Paper

We’re having another hot and relatively humid week in  Northern Michigan today,  and I know other parts of the country are currently experiencing something like a steam bath.  Humidity levels have reached 100% on some days,  and dew points are very high.   That type of weather is generally pretty uncomfortable for humans,  and it doesn’t do your sublimation supplies, like paper,  all that much good either.   Since the weather has provided me with a ready made subject,  I thought today would be a good day to discuss humidity and sublimation paper.

First of all,  let’s discuss what humidity does to sublimation paper.    Your sublimation paper can retain an enormous amount of moisture,  so  exposing it to humid air is like setting a sponge in a pool of water.    Excess moisture in your paper is not a good thing and can lead to problems like color shifting (colors lose accuracy), bleeding of the image, and uneven transfer of solid filled areas. If you can,  store your sublimation paper in a temperature and humidity controlled environment.   If that isn’t possible,  try to avoid humidity related problems by keeping  your sublimation paper  sealed in a plastic bag.

If you paper is exposed to humid air and does soak up some excess moisture,  you have a couple of options.  One is to 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.  If you’ve already printed a transfer  you can try to save the transfer by heating it in your heat press.   To eliminate the excess moisture,  place the printed transfer 2″ to 3″ below the heat platen for 30 – 40 seconds.   When you do this,  the result may be that the colors in the transfer appear washed out or faded.  This is normal and the anticipated result of color adjustment for the transfer process.

As a general rule,  the optimum environment for sublimation printing is one that has low humidity and is reasonably cool.   You may have to do some experimenting to find the correct humidity and temperature levels for your particular climate.

Sublimation Tip Sheet 4/15/10

Over the years that we’ve been doing sublimation, we’ve learned a lot.  Some of what we’ve learned needs to be explained in detail, and is best suited to a longer blog post.  Other tips and tricks are just small bits of information that don’t necessarily merit their own post,  but could still be useful.   Because we still want to share these tips and tricks with all of you, I’ve created the Sublimation Tip Sheet.  These posts will appear whenever it seems necessary, and will include various sublimation and ChromaBlast tips and tricks which will help you get the most out of your printers, inks, papers and heat presses.

Tip 1:  Sublimation Paper Storage

Properly storing your sublimation paper is important, and can significantly affect the results you get when you print and press.  Most paper can absorb humidity, and depending on the coating, some absorb a lot more than others.  As a general rule, best practice is to store your sublimation paper sealed either in the original packaging or in a reclosable bag in a dark area in a climate controlled office or other area.  Moderate humidity in the 40% range and temperature around 70 degrees with low or no light, is usually considered ideal storage conditions.  Realistically however, these conditions may not be practical, so just try to get as close to that type of environment as you can reasonably achieve, and you should be good to go.

Tip 2:  Heat Press Temperature

A heat press with an even temperature is a vital part of sublimation success, but not all heat presses heat evenly.  To make sure that your heat press does not have hot spots or cold areas which could have an impact on the evenness of your sublimation print,  check your press frequently with a pyrometer.   Taking a few seconds to check the temperature of your press could save you a lot of frustration and wasted blanks.

Tip 3:  The items you sublimate should be Polyester or Poly Coated

This seems like a pretty elementary fact, but I see this question on forums all the time.   For best results, whatever you sublimate should be 100% polyester fabric or should have a poly coating.  If you sublimate a garment that is some percentage polyester and some percentage of another material, the sublimation ink will only bond with the polyester fibers.   This can lead to a patchy,  faded graphic.   Attempting to sublimate a mug or a mousepad that does not have a poly coating will most likely not work at all.

If you have a sublimation or ChromaBlast tip or trick that you’d like to share,  please leave it in the comments or e-mail me at kristine dot shreve at myenmart dot com.