Travis, that sandpaper method is exactly how I make mine too 😄 You’re already doing it the artist way.

Here’s the thing about those grades. An 8B label describes a pencil lead, not powder. Ready made powder is usually sold as one ungraded type, which is why you can’t find an 8B container anywhere.

So keep doing what you’re doing. Pick the pencil grade you want, 2B, 4B or 8B, rub it down and you get powder of that exact grade. Simple, and much cheaper than buying it.

Since you want containers ready to go, build a little set in advance. One small jar from each grade you use most, with a label on each, so the exact grade is always on the shelf when you need it. And if you use a lot of powder, graphite sticks give you more material per rub than pencils, and a small lead grinder can replace the sandpaper if you want something more permanent.

You can try using woodless pencil to make the powder