If you are looking for a good paper store right in the city social graces is a good choice. Located right in Hillsboro Village they've got a full line of most major papers, stationaries, and cards.
The service is usually alright when I go in there, but it's nothing that will knock your socks off. The store is very full of racks, tables and displays so if you don't like cramped spaces you might not like it because there are a few tight squeezes as you browse the store.
However if you've are strolling through Hillsboro Village it's definitely worth stopping in, you never know what you'll find inside.