Alizarin Crimson
Unfortunately PR83 has been discontinued. How long a given manufacturer will be able to offer a paint with the original formulation will depend on how much of this pigment they have in reserves. Update from Williamsburg in fall 2023: “Good News: We secured a final purchase of the discontinued Alizarin Crimson pigment. By our best estimate, we believe we’ll have sufficient supply for the next two years. We will monitor and keep all informed.” As with all Alizarins, this color is not lightfast. We wanted to make a note on its texture though. Williamsburg categorizes this color as 'Medium' for texture (next stop is coarse). Other colors in this same medium category are fairly gritty, however their Alizarin is not. This paint has a smooth feel with the palette knife.
In 2023, Golden published a vital series of tests on their colors and how they performed in mixes with various white paints. There is a lot of information about Alizarin specifically. More information can be found at https://justpaint.org/astm-lightfastness-testing-for-oil-paints/.