Screenprinting tips

screen-printing-pressMost sweatshirts, hoodies, and performance garments contain a percentage of polyester, for its strength and stability. It is also more colourfast than cotton in normal wash and wear.

However garments with a polyester content need more care at the high temperatures associated with screenprinting. If overheated, dye from the polyester can ‘migrate’ into the ink. This can appear immediately after the ink is cured, or hours or days later.

To prevent this:
* Print with low-bleed, high opacity inks designed for printing on fabric with a polyester content.
* Use no more heat than necessary to cure the ink; max 160 degrees C.
* Print and flash-cure a low-bleed white or similar under base, then print the desired color.

Softshells require additional care to prevent dye migrating into the print, particularly if the print is a light colour and on a dark fabric.
Using a cold cure catalyst is recommended to enable drying without the aid of heat.

If you do need heat, proceed with caution:
* Use a high opacity grey base blocker first, followed by a white base blocker.
* Do not flash for more than 2 seconds.
* Garment temperature must not exceed 160 degrees C. Note if dryer is set at 160 degrees, this will be the temperature at the sensor – areas of the tunnel may in fact be hotter, and the temperature will need to be lowered to compensate.
* Allow garments to cool separately before folding or stacking.

Heat transfers on softshells:
* Use a vinyl with a blocking barrier layer to prevent migration.
* Garment temperature must not exceed 160 degrees C.
* Reduce time in press to minimum required to achieve full adhesion.