There was a time when a lunchbox was just that, a box into which your parents packed your lunch.

For many years they were metal and came emblazoned with your favorite cartoon or movie characters, as well as a matching thermos. By the ’80s, metal was passe, making way for plastic. But the basic design was the same. And you liked it. Until you were old enough to not. Then you graduated to paper bags or ditched packed lunches entirely for some atrocious pizza-chicken-cheese-nugget-potato thing from the cafeteria.

Lunch gear has come a long way since those days. Today’s lunch “systems” are dominated by bento-style gear, which originated in Japan and involve multiple compartments and containers to hold a variety of foods. And that makes sense for modern kids, who are as likely to be toting sushi and DIY taco kits as they are the classic PB&J.

The gear also is far more high-tech. Today, everything from the bag to the water bottle is super-insulated and rated so you know how long your darling child’s pasta carbonara will stay warm and how long the organic juice will remain chilled.

Which isn’t to say all modern lunch gear is the same. So I’ve assembled a few pointers to help you make the best choices as you brace for another year in the lunch-packing trenches.

Boxed in

Bento-style containers rule. Having lots of little compartments to fill may sound intimidating, but it’s easy. Some crackers go in one, cheese in another, maybe something fruity in a third. Toss leftovers from last night’s roasted chicken in a fourth and before you know it lunch is packed in all of about five minutes. That’s the power of bento; it lets you think small. And faster than you expected, you’ve assembled a meal.

For preschool and other young kids, consider a kit such as Laptop Lunches (LaptopLunches.com), which packs multiple containers inside an easy-to-open clamshell box. They are affordable, dishwasher safe, indestructible and come with their own insulated carrying bag.

Older kids require more food and flexibility. For them, LunchBots (LunchBots.com) rock. These stainless-steel containers are available in numerous configurations that can be combined in endless ways. They can be pricy, but will last forever (think fourth grade through grad school).

Looking for a budget option? Check out the disposable food-storage containers at the grocery store. Many companies now offer bento-like containers you can easily mix and match for lunch duty. Bonus: When Junior loses them, you don’t lose a mint.

It’s in the bag

Insulated lunch bags are where it’s at. Some lunch kits, such as Laptop Lunches, come with custom bags. But if you’re assembling your own container collection, you’ll need to shop around. For younger children, a basic insulated bag with a zipper closure should be fine. Combined with an ice pack, these are good for keeping yogurts and other perishables cool.

For older kids, you may need to dig a little deeper. When my son transformed from a peckish preschooler to a voracious middle schooler, I needed a serious upgrade in packing space. I searched online for hours before settling on a “picnic bag” that would allow me to pack a sufficient amount of food.

Whatever your needs, it’s wise to go with a bag that offers two compartments (often divided as bottom and “lid”). This allows you to separate warm and cold items (such as a chilled yogurt cup and a warm soup), as well as segregate easily bruised fruits from hard items.

Liquid intelligence

Lunch liquids generally take two forms — drinks and soups/stews/chili. You’ll need gear for both.

For drinks, the best bet is Hydro Flask (HydroFlask.com), which offers a line of insulated water bottles so good they are almost scary. As in, I’ve left an ice water-filled bottle in the blazing sun on my driveway for six hours and it still had ice floating in it. Looking to pack milk or juice and make sure it stays safely chilled? This is your bottle. They are rated to keep liquids cold for up to 24 hours and hot for up to 12 hours.

For soups and chili, I’m a fan of Thermos brand’s Foogo food jars (Thermos.com). They are a great size for kids (available in 7- and 10-ounce versions), affordable, easy to open and keep foods hot for five hours.

The numbers

Packed lunches are great. Food poisoning isn’t. Making sure the former doesn’t trigger the latter is just a matter of knowing your numbers.

Cold food needs to stay below 40 degrees Fahrenheit. Hot food needs to stay above 140 degrees Fahrenheit. Once food falls outside those ranges, it’s safe to eat for another two hours.

So when you shop for lunch gear — insulated lunch bags, thermoses, water bottles, etc. — buy only products with thermal ratings that cover the range of time between when you pack the lunches and when they’ll be eaten.

The little stuff

We tend to focus so much on the gear and bags, we forget the little things like utensils and ice packs.

Obviously, this isn’t the time to break out any silverware you don’t want to lose, but disposable plastic isn’t all that eco-friendly. Hit the second-hand shop and grab some inexpensive stainless-steel forks and spoons for pennies.

As for ice packs, you’ll want one even when using insulated lunch bags. Get several so you always have one in the freezer. Rigid packs are better than soft, which can freeze in awkward shapes. They also are less likely to be punctured when your child decides to launch his lunchbox across the schoolyard (and if you think that won’t happen, you’re delusional).