When comparing the materials, screen printing on polyester is one of the most challenging tasks to deal with. Sometimes, it is not recommended to do so. However, in the printing industry where buyers’ preferences are diverse, it is essential to know how to print on different types of fabric and techniques to achieve the best results.
In the past, polyester was mostly used in producing certain types of clothing. Since 1952 when first introduced to the American public, it has been famous for its durability, wick moisture ability, and wrinkle resistance. In modern times, polyester is incorporated with a lot of popular garments to help smoothen the materials.
With all those popularity, when screen printing on polyester fabric, there are cautions to take notice of. So, if you want to take on this challenge, read below to better prepare your production run.
Can you screen print on polyester?
In reply to the question almost every screen printing firm asks at first, the answer is yes. It will definitely take more effort and set-up time than sublimation or digital printing. However, when it comes to printing large quantities, it can save you a considerable amount of money. You need to choose special additives and inks as well, which will be mentioned in later parts.
Why is polyester hard to screen print?
If it is totally possible, why must we take notice of so many aspects when screen printing on polyester shirts? The answer lies in a reaction called dye migration.
It happens when small dye particles from the garment seep through the screen print ink, which causes unwanted changes in how the print turns out. For example, when printing white ink on a red t-shirt, if you see the white ink turned red from the shirt color, you’ll know dye migration has occurred (1A).
This situation usually happens when the garment is overheated during the curing process (the process of putting the fabric on a conveyor belt that runs under the heat set to wash the screen print ink). While the heat needed for the curing process is 320 degrees, dye migration usually occurs when reaching 300 degrees.
Since curing is a required process of screen printing, to avoid undesirable results, you need to pay attention to the preparation and set-up steps.
Tips on how to print on polyester
With all of those being said, here I have gathered what you should keep in mind when screen printing on polyester to get the best quality results.
Pick the right polyester screen printing ink
Before proceeding with printing in bulk, it is important to experiment with different types of ink. Your choice should be based on your targets.
Plastisol ink is brighter and requires less time to work with, while the water-based type is softer and more eco-friendly. To know more about these two’s characteristics, come read my Water-Based Vs. Plastisol Inks – What’s The Difference? article.
You’ll need your ink to not bleed when starting to print. When printing the ink on polyester, a moisture-wicking material, water-based ink often dry out faster than plastisol one. Therefore, it’ll need an underbase for better production.
About the underbase you choose, it should be one-stroke white or gray to help prevent dye migration. This is because the one-stroke white underbase can let any plastisol ink apply to it. At the same time, the grey one can help slow down dye migration thanks to its thickness and ability to dry at low temperatures.
Choose a suitable fabric when printing on polyester
There are various difficulties that exist with printing on each kind of polyester blend materials.
The fiber ratio can make a real difference among the printing results. Mixed materials may make it hard for the ink to absorb properly. So, to avoid curing issues and dye migration, color-changing, or bleeding, choose the blend that has more than 65% polyester. If you want to try fabrics with a lower ratio than that, consider switching to other printing techniques.
After choosing your fabric, again, test the inks you use to prevent color bleeding situations.
Pay attention to the ink drying process
As mentioned above, dyes will migrate when the fabric is heated up to about 300 degrees. So, to stop this from happening, only flash your image onto the fabric when it needs to cure.
A few additives you can use to gauge the temperature and cure the ink are a temperature tape and a permaset synthetic fixer. Equip these so that all unwanted circumstances are avoided.
Keep artwork still during the heating process
During the curing process, it is necessary to add a slip sheet to keep your design flat when printing on a synthetic material like polyester. It is a slight piece of paper to place inside the garment and under your artwork. Remember to use it all the time, especially when printing white ink on dark garments.
In conclusion, there are many difficulties you will encounter when screen printing on a challenging material like polyester. However, the results won’t let you down as long as you got everything prepared and tested beforehand.