Hello,
I am planning to color concrete for outdoor casting. I did a search and found some suppliers of pigments for concrete. For example, iron oxide for blackening is named as 540 or 722. This is probably just a designation. What makes me wonder is the difference in price between the companies. The price per kilo varies between about 360 - 180 SEK. Is there any difference in quality between the pigments, or can one assume that all are equivalent?
