Crane Silver rag is a lustre paper, so not in the same catagory as Portfolio Rag (CPR) and Max(CMx).
Both matte papers are on non OBA cotton bases, so a little off white. CPR is a little whiter. ItsD Max is a tad greater. This may be a more recent coating , as CPR is the more recent paper, but it couldd be just that CPR is a little smoother. All other things being equal the smoother the paper the greater the gamut and density range. In practice no-one notices any difference in print quality between these 2 papers. The reason for choosing one over the other is personal taste in paper surfaces. CMx has a slightly more textured surface, which is a bit more "random". The texture on CPR runs in the direction of the grain. The surface of CMx is softer than CPR but nowhere near the softness of Hahnemuhle Photo Rag (HPR). HPR has optical brighteners (OBAs), but these don't work under tungsten light.
In summary CMx and CPR are both excellent papers. Choice between them and other leading papers such as HPR, is really just personal. Behing glass and with gallery lighting, it's almost impossible to pick the difference.
HTH
Brian
PS If you are comparing paper prices on rolls, Crane papers are in 15m lengths, and a lot of other art papers in 12m lengths., so it can pay to calculate price per square meter.
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