PY 109 – isoindole yellow PY 109 – isoindole yellow This isoindolinone class of pigments were developed in 1946 and commercially available in the 1960s Manufacturer/ product code: Kremer / 23340Chemical Description: isoindolinoneColor: yellowColor Index: PY 109Date: from 1964 Reflectance Spectroscopy (350-950 nm) Reflectance Spectroscopy (200-1250 nm) Reflectance Spectroscopy (950-1700 nm) XRF Spectroscopy Raman Spectroscopy (532 nm) Raman Spectroscopy (785 nm) Raman Spectroscopy (830 nm) Raman Spectroscopy (1064 nm) FTIR Spectroscopy (non-invasive )