The reader question
The two materials go side by side here on the six things that actually decide the answer — weight in a work bag, reheating, stains and smells, breakage, lid seal, and price. Plastic wins more of those than people expect. Here is the fair version, then what we sell.
The comparison
Same lunch, same three containers. In every photo below, glass is on the left and plastic on the right.
Glass is noticeably heavier than plastic — an empty glass container is a weight you can tell apart in your hand — and that difference is on your shoulder all day. Carry two or three meals in and the bag is heavier by the time you reach the office.
If you walk, cycle or take a packed train, weigh this one first. Nothing else on this list changes your morning as much.
Left: glass. Right: plastic. Same volume.
Glass goes into the microwave as it is, and because the container stays cool you can lift it out with bare hands. It also goes into a conventional oven without the lid — useful if you want to crisp something back up rather than steam it.
Plastic reheats fine, but lids usually have to come off, and a thin container can flex when the food is hot. Neither material enjoys an oven: plastic should not go near one.
Left: glass, lid off, straight in. Right: plastic, lid off too.
This is where glass earns its keep. Tomato sauce, curry, beetroot — glass holds colour on its surface for a wipe, not a soak. It also gives up smells: an empty glass container smells like an empty glass container.
Plastic is porous enough that oils work into it over months. A tomato-heavy week will leave a faint orange ghost that no amount of washing-up liquid removes, and last night's curry tends to linger.
Left: glass after curry. Right: plastic after the same curry.
Glass can break. Drop it on a tiled kitchen floor and you are sweeping. Borosilicate handles temperature changes far better than ordinary glass, so it does not shatter from hot food in a cold container, but a knock off the counter is still a knock off the counter.
Plastic in a work bag, at the bottom of a rucksack, in a child's hands: it survives. That is a real advantage and it is worth saying so plainly.
Left: glass, dropped. Right: plastic, dropped.
Both types seal well when they are new and undamaged. The difference shows up later. A glass container keeps its rigid rim, so the rim holds its shape through years of washing and a lid that presses on snugly today goes on snugly later. A plastic container deforms slightly in the dishwasher and the seal loosens with it.
Practical caveat: any lid, on any material, will leak if you fill the container to the brim or put soup in it sideways. Leave a finger's width of headroom.
Left: rigid glass rim. Right: plastic rim after the dishwasher.
Plastic simply costs less per container. If you are kitting out a shared kitchen or buying for a student flat, that gap is the whole decision.
Glass costs more up front. Whether it costs less over time depends entirely on whether you keep it — which is the honest answer, not a sales one.
Left: glass, bought once. Right: plastic, bought often.
Where plastic is the better choice, plainly.
Plastic is lighter to carry, cheaper to buy, and it does not break. If your containers travel in a rucksack, get knocked around, live in a shared fridge, or you just need a lot of containers without spending much, buy plastic and do not feel bad about it. There is no version of this comparison in which plastic is the wrong purchase for everybody.
Short guide
Two honest verdicts. Neither is a consolation prize.
Plenty of people keep both: glass for the fridge and the microwave at home, one or two plastic boxes for the days the commute is long.
If you landed on glass
We make glass containers, so this is the part of the article where we talk about ours. It is one option among many, and the comparison above still stands as written.
The Starter Set: eight containers in four sizes, with snap-lock lids.
Starter Set
$59
Eight borosilicate glass containers, four sizes, eight snap-lock lids.
Eight-piece set, $59. Lids are replaceable on their own if one goes missing.
The glass base takes the oven; the lid stays off.
Four sizes, two of each. The numbers are the ones that matter when you are portioning a Sunday cook into weekday lunches.
Small
Sides, dips, cut fruit.
Medium
A single lunch portion.
Large
Dinner, or lunch plus a side.
Deep
Soup, stew, batch leftovers.
On the lids
The snap-lock lids press on flat and come off with a tab, so you are not prizing at a corner with a knife. They are the part that wears first in any container, which is why we sell spares separately — you replace the lid, not the box.
Lids stay off in the microwave and off in the oven. The glass base is the part that goes in both.
Snap-lock lids: press flat, lift at the tab.
Back to the question
Eight borosilicate glass containers in four sizes with snap-lock lids, and glass bases that go in the oven without the lid. Spare lids sold separately. If your answer was plastic, the note further up still holds — buy plastic.