Banks make money selling you checks and deposit slips. In fact, back in the early days of "free checking" the cost of checks was padded to help cover the cost of free checking.
But then, many consumers discovered third party check printers, and that sort of spoiled that party.
Many banks still offer to print checks and deposit slips, the cost is often not trivial. I recall actually having a box of these printed up, and my bank charged me $30 for the privilege!
Since then, I have taken to using the generic slips they have in the lobby. It takes only a second to fill out the account number and name.
Bank of America - everyone's favorite whipping boy - has one of the best electronic banking networks on the planet. Say what you want about the Countrywide debacle, their ATM network is extensive and easy to use.
Best of all, you can deposit checks into it by just slipping them in a slot, where they are scanned and then displayed on the screen. The money is credited the next day, and you get an image of the check on your receipt.
No envelopes, no deposit slips.
Of course, paper checks are rapidly disappearing from the scene these days. Direct deposits, online bill-pay, and debit cards are far easier to use. And it looks like BoA's threat to institute debit card fees was a total bluff - which people called them on, and they folded, like a cheap tent.
Perhaps this is a trivial area of savings. But I refuse to pay for deposit slips!