Some people are clearly reluctant to lend things. Others have an open-drawer (or -closet or -garage) policy. But what if you’re somewhere in between? Sure, your neighbor can take your power mower for an hour, but you don’t want a colleague waltzing off with Grandma’s pearls for a week.

When asked for a favor, give some thought to how important an object is to you before you answer. “It’s a terrible idea to lend an item if it would kill you to have it damaged,” says Amy Dickinson, author of the syndicated newspaper advice column Ask Amy. In fact, go so far as to equate lending it to losing it. “I simply don’t lend anything that I can’t afford to part with, period,” Dickinson says. So if your sister-in-law asks to borrow your worn-once Lela Rose dress, but a check won’t equal the value and she can’t replace it off the rack, don’t allow it out of your closet.

If you feel uncomfortable, guilty, or petty saying no, just give an honest explanation, like “It’s a treasured family heirloom, and I wouldn’t trust my own grandmother with it.”

Another good question to ask yourself is If this gets ruined, will it also ruin our friendship? If the answer is yes, don’t lend it. That said, if Sue wants to borrow a 13-by-9-inch baking pan (you do have three of them) and you never get it back, you can chalk it up to neighborhood karma.

Of course, the responsibility truly lies with the borrower — and we’ve all been one at some point. The rule is simple and unforgiving: “If you borrow something, you must guarantee to return it on time in its original condition,” says Dickinson. And have the good sense to recognize a reluctant lender (hemming and hawing are two good clues) and forgo the transaction. Your friendship will thank you.