Why use Plastisol Inks?
Most Pantone mixing formulas call for use of transparent white ink, but many letterpress printers choose to use opaque instead. One reason to use opaque white is that the mixed colour—off press—may resemble more closely the printed colour, though the mixed ink will not be perfectly opaque once printed. When printing on an off-white t-shirt, the opaque white helps the ink colour to retain its hue instead of allowing the colour of the t-shirt to show through. Use transparent white if you intend to do overprinting to mix colours (ex: yellow and blue to make green), or if the printed image is meant to be translucent.
Keep In Mind:
Fabric: No restrictions
Cotton – Low
Blends – High
Polyester – High
Recommended: Very low restrictions when printing
Keep in mind: Thin fabrics with a large surface area creates a heavy deposit of ink. It tends to lose sharpness the more layers of ink there are, especially on thicker fabrics.