1050 is pure aluminium and is very gummy. Lots of WD40 or cutting fluid required, verging on a continuous supply, and expect a bit of cleaning up with a debur tool after.

Thin sheets are usually 1050 (as it bends nicely), thicker sheets say >5 mm are often 6061 which is much nicer to cut but depends on what you are making. 5000 series also cuts OK but will again be thicker (in my experience).