Digi Coat Spray White Base Mattifying 400 ml.
This product creates a white substrate, it is used to treat dark substrates not suitable for sublimation printing (ie not in polyester): metal, glass, wood, ceramic.
Just spray the product evenly on the surface you want to print in sublimation and then use the Transparent Polyester Spray.
The spray should be applied evenly on the product, with movements from left to right, starting from top to bottom.