Understanding Glycol Sweating in DTF Transfers: Causes and Fixes
Have you ever noticed that your DTF transfer film feels wet, greasy, or slippery before or even after pressing? This common issue is known as glycol sweating, and it can affect the overall quality of your prints.
What Causes Glycol Sweating in DTF Printing?
The problem usually comes from oversaturation of ink. During the printing process, glycol (a carrier in DTF inks) doesn’t fully evaporate in the dryer. Instead, it gets trapped between the PET film and the melted adhesive powder. Over time, this creates a greasy or wet feel on the transfer, which can still be noticeable even after pressing and peeling.
Another sign of glycol sweating is when water spots appear on your print after pressing. Some printers try to fix this by using a cover press with a thin cotton sheet to absorb excess moisture. While this may reduce spots, it often doesn’t completely eliminate the issue.
The Real Fix for Glycol Sweating
The root cause comes down to how your white ink underbase is generated. When too much white ink is layered under already saturated colors, the total ink load becomes excessive.
For example:
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A solid black area typically contains 30% each of cyan, magenta, and yellow plus 100% black.
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If you also add 100% white underneath, your print is overloaded with nearly 300% ink coverage.
This heavy saturation prevents proper drying and leads to glycol sweating.
Solutions to Prevent Glycol Sweating in DTF Printing:
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Adjust your white base layer → Generate a proportionate white underbase instead of 100%. This balances ink coverage and reduces oversaturation.
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Reduce white ink percentage → Lowering white ink output helps, but keep in mind that it may reduce print opacity.
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Increase dryer temperature or dwell time → Higher drying settings can improve evaporation, but this may prevent you from using hot peel DTF transfers.
Final Thoughts
If your DTF transfers feel greasy, sticky, or show water spots, the issue is not your film or powder—it’s ink oversaturation. By adjusting your white ink underbase and optimizing dryer settings, you can eliminate glycol sweating and achieve cleaner, longer-lasting DTF prints.