I've been using PrecisionInks for 10+ years. It is an old school family business and never once disappointed me. I use this spectrophotometer for calibration:

I've been using PrecisionInks for 10+ years. It is an old school family business and never once disappointed me. I use this spectrophotometer for calibration: https://www.bhphotovideo.com/c/product/1369004-REG/x_rite_eostudio_i1studio.html https://www.bhphotovideo.com/c/product/1369004-REG/x_rite_eo...