Union Ink Company Announces New HS-A Ink Mixing System. Union’s newest addition to our environmental friendly screen printing ink line, the PVC-Free HS-A (High Solids Acrylic Rubber Ink) inks are suitable for printing with very good opacity and brilliant colors while keeping a supple hand when printing on dark 100% Cotton or 100% Polyester garments. This durable ink prints wet-on-wet and has extremely good stretch. Our booth # has changed, stop by Booth 1030 see to what's NEW!