Accounting for targeted income.

[Buddha Buck]

This may be the wrong place to ask this, as I know how to do what I want in
GnuCash, I just don't know what I want.

How does one account for a coffee kitty?  What I mean is a a box where
people toss in money for coffee they use, and periodically the company buys
coffee to replenish the supply out of the funds so contributed.  In my
situation, it's not coffee in question, but another consumable -- plastic
for use in a 3d printer.  I don't want to leave the box full of cash
around, so I want to periodically collect the funds from it and deposit it
-- and write checks for the replacement plastic out of the main checkbook.

I see a couple of options:

1) Have a Expense:Printer Supplies account and an Income:Printer Kitty
account, and just sort of know they are related.

2) Have an Expense:Printer Supplies account and an Expense:Printer
Supplies:Kitty contra-account.

Any opinions?