Phthalocyanine Blue RS
This color is one of two phthalo blues offered by Blockx. This pigment is more associated with the redder form of Phthalo Blue. The other Blockx phthalo is called Primary Blue, PB15:3. Once upon a time we used to have a Blockx color chart with swatches of every color. The phthalos were notable in that they did not yellow in the dark as other paints did, which is especially noticeable in the blues. As a general note on binding oils: some of the paints in Blockx’s range are bound in linseed oil and some are bound in poppyseed oil. An artist should educate themselves on the benefits and drawbacks of both oils. In general, linseed oil tends to form strong paint films, and poppyseed oil is not known for this. Linseed oil tends to yellow, and one of the main draws to poppyseed oil is that it resists yellowing to an amazing degree. However in some cases there are reports of problems with drying that are associated with poppyseed oil. Please research both oils so that you know what is right for your art practice. Blockx’s range is a gorgeously chromatic and unique addition to the world of oil paints, and we especially love their non-yellowing formulations in blues and purples.