Ink Adhesion Testing is a free service provided to our customers. Contact your Sales Representative or call Customer Services to find out about this service. Below is additional information regarding surface material structure.
The surfaces of plastics and other materials vary not only in terms of texture, but in terms of surface tension, too - a characteristic also referred to as "surface energy" or "surface wetting".
If the surface tension of a substrate is lower than the surface tension of the ink, the ink won't stick. It's a sign of inadequate chemical covalent bonding & "bad ink adhesion," in layman's terms. Likewise, if the substrate is wettable, that is, if it has high surface energy, the ink will adhere properly to the surface, allowing it to be marked or decorated.
One simple test of a plastic's printability is to drip some water on the surface. If the water beads up, the surface energy of the substrate is lower than the surface tension of the water, and vice versa. If the water "sheets" its surface tension is lower than the substrates'. Beading is bad. Sheeting is good.
The scientific test is to check the surface of your plastic using a dyne kit (image above). These specialized dyne markers contain a fluid that mimics ink adhesion and allows printers to choose the type of ink that will most likely stick to the product's surface.