Blue ice is the good stuff — dense, old, and mostly air-free, the kind that takes a screw like it was meant to. But "blue" is not a permission slip. It's a sign to read more carefully, not less.

What blue means

Blue ice forms when meltwater refreezes and squeezes the air out. It's strong, but it's also what carries the most load — and the most sunlight. A blue face on a south aspect by 2 p.m. is a different route than the same face at 7 a.m.

Read the edge

Where the blue ice meets the rock, or where it thins at the top, is where it fails. The color doesn't fade at the edge — it just stops being supported. Set your screws in the body of the ice, not the margins.

The short version

Blue is beautiful, blue is strong, blue is still water. Check the aspect, check the hour, and respect what a warm sun does to the thing you're hanging from.