Stormin Mormon wrote:
I'm no painter. But, the one time I used them I could dip
them straight into the paint can. I also covered a lot of
wall in a hurry, actually. No rolling pan needed. Worked,
for me.

I found the rollers from one store would not fit the handle
from the other store.

That works, but in general one should avoid painting from the can: Oxygen is
the enemy of paint!

Assuming latex paint, when ready to return the can of paint to storage,
follow these procedures to mitigate oxygen destruction:
1. Lay a piece of plastic over the upturned lid (cling-wrap, bit of plastic
bag, etc.).
2. Spray the plastic with PAM (original, not the garlic-flavored model)
3. Exhale into the can three times (to displace the oxygen with CO2)*
4. Hammer on lid with the plastic.
5. Invert can and store upside-down.

The PAM will migrate to the top of the paint and form a thin oil barrier
against any remaining oxygen in the can.

--------
* Or a squirt of nitrogen or argon gas (found in all well-equipped
workshops).