IRWINTools IRWIN STRAIT-LINE Marking Chalk, Permanent Staining, Crimson Red, 4 lbs (4935525)

Really love to use the strait red color. For concrete slabs and walls tends to last through the poor vs the blue can be hard to see as you pour. Good price on amazon as well.

It’s perfect. It’s the best balance of permanence on the substrate and the least amount of coloring yourself throughout the day. Black shows up so well, but you look like you came out of a coal mine by lunch. This is the solution. Very permanent, but not on you!

I wanted a chalk that stayed longer when laying out floors and it was perfect

My main complaint was difficulty finding the line while wet (wet as in a rainy day). The line stayed well enough after but especially the black was difficult to reference while wet. The cost made it hard to refuse but it’s my guess that I will loose this container before I utilize all the chalk.

As described

We mark concrete slabs for large wet sawing machines. These chalk lines are very bold against the cured concrete, and are fairly durable as-is. Once sealed with a misting of clear spray paint, these cut lines hold up very well to brooming, foot traffic, vehicle traffic and slurry removal. The best chalk for this purpose.

Me gusta más el polvo negro que el azul la marca queda más limpia buen compra

Instead of expensive mica powders, I use carpenter's chalk to produce colored epoxy which fills and strengthens defects in turned pieces. Works great and produces intense colors with only a very small amount of chalk mixed in clear epoxy.