SpectraFix casein-based fixative is a non-toxic workable fully archival fixative for soft and oil pastel charcoal conté coloured pencil graphite chalk gouache watercolour or any other delicate media. Works on paper canvas Yupo glass ceramic stone leather wood fabric (not washable) etc. Use it under oil paints or acrylics to prevent underpaintings from smudging or to layer in other media. Not suitable as a final varnish on top of oils or acrylics. Made from an antique recipe used by French artist Edgar Degas in the 1800s SpectraFix is favoured by professional artists for its unique ability to permanently hold pigments without dulling colours and because it is all natural and odour free you can spray your project indoors while you work. No more odours or unhealthy fumes. 12 fl. oz / 360ml.