Though grocery shopping experts have long touted buying store brands as a great savings strategy, consumers are finally paying attention. Maybe too much attention.

Nearly 40 percent of shoppers purchased more store-brand items over the past year, according to a new survey from research firm Accenture. Two-thirds of shoppers say half of what they buy carries a store-brand label.

The main reason: the prices beat those of the big brand names. In most cases, consumers aren’t sacrificing taste, either, because the same big brand producing say, canned veggies, is also responsible for packaging the store’s line.

“Quality has really gone up, ”said Jill Cataldo, founder of Super Couponing workshops. Stephanie Nelson, the founder of CouponMom.com, agreed. “Some stores actually have several tiers of private labels,” including gourmet and organic products, she said.

But in some cases, consumers are better off sticking with the brand names they know and love. Those trying out store brands should “start small,” Cataldo said. “Buy one, not 12, to make sure you like it.”

Here are five product categories that may warrant caution:

1. Paper products

Store-brand paper towels, paper plates and other goods can be of varying quality. The toilet paper rolls are often smaller and lighter, said Teri Gault, founder of price-tracking site TheGroceryGame.com. Plates might be flimsier, and towels or tissues may be less absorbent, meaning you’ll need to use more than you might with a brand name, negating savings.

2. Cleaning products

Consumers tend to prefer brand-name laundry detergent and other cleaning products, Nelson said. The risk: the store brands sometimes are often not as strong, she said.

3. Coupon-heavy items

Store-brand items might not be cheaper after all. “The right coupon and sale combo is key,” Cataldo said. “I still do better on the whole buying national brand instead of house brand.” That combination beats even low store-brand prices. Some stores do offer coupons on their own brands, too, so be sure to compare prices regularly, she said.

4. Macaroni and cheese

Boxed macaroni and cheese is one of the few categories where shoppers across the board tend to be brand loyal, said Nelson. “It’s Kraft all the way,” she said. Gault said complaints she has heard fault store brands for being “too orange,” and not that cheesy.

5. Diapers

Some parents love store-brands, Nelson said, but others complain of leaks. Retailers and manufacturers market heavily to new parents with coupons and loyalty rewards, too, so buying store-brand diapers may not be the cheaper option.