Choose latex when you need lots of balloons for a garland, arch or ceiling of color, and foil when you want one or two shapes or messages that stay up for days. With helium, an untreated 11 to 12 inch latex balloon usually floats for about 8 to 12 hours, while a foil balloon commonly floats for several days to a week or more. Filled with air, neither type floats.
What’s the difference between foil and latex balloons?
Latex balloons are made from natural rubber. They stretch as you fill them, you close them with a knot, and they come mostly as rounds in sizes from about 5 to 36 inches. Because latex is slightly porous to helium, the gas slowly escapes through the skin itself.
Foil balloons, often called Mylar, are made from thin plastic film with a metallic coating. The film doesn’t stretch, so the balloon has a fixed shape, which is why foil comes as letters, numbers, cakes, animals and characters. Most have a self-sealing valve: a thin internal sleeve that closes by itself when you remove the straw or nozzle. The film holds helium far longer than latex does.
Foil vs latex at a glance
| Question | Latex | Foil |
|---|---|---|
| Helium float time (planning figure) | About 8–12 hours for untreated 11–12 in | Several days to a week or more |
| Floats on air? | No | No |
| How it closes | Tied knot | Self-sealing valve or heat seal |
| Shapes and messages | Mostly rounds, some printed patterns | Letters, numbers, shapes, printed messages |
| Reusable? | No, single use | Often yes, if deflated carefully and not punctured |
| Garlands and arches | The standard choice | Used as accents |
| Sun and heat | Turns cloudy in direct sun; heat causes pops | Gas expands in heat and can split seams |
| Cold | Shrinks slightly | Looks deflated and wrinkled; recovers when warm |
| Allergy note | Contains natural rubber latex | The usual pick when a guest is allergic to latex |
| Power lines | Not conductive | Metallic coating conducts electricity |
How long do helium balloons float: foil vs latex?
For an untreated 11 or 12 inch latex balloon, about 8 to 12 hours indoors is a sensible planning figure, so fill latex on the day of the party, ideally within a few hours of guests arriving. Larger latex balloons hold more gas relative to their surface and float longer. Balloon shops often coat the inside of latex balloons with a liquid sealant that slows the leak and can stretch float time well past a day.
Foil balloons lose helium mainly through the valve and seams, which is far slower. Several days to a week is common, and well-sealed balloons often go longer. That makes foil the practical choice when you want to fill balloons the night before, or when a centerpiece needs to last through a weekend.
As a size guide, an 11 to 12 inch round latex balloon holds about half a cubic foot of helium when fully round. Disposable helium tanks list how many balloons of each size they fill, so check the label against your count before you buy.
Can you fill foil and latex balloons with air?
Yes, and for most decorating, air is the better choice. Air-filled balloons don’t float, but they don’t lose lift either, and they last longer. Air-filled latex garlands kept indoors usually stay presentable for several days. Air-filled foil balloons often stay full for a week or more indoors, because air leaks through the film far more slowly than helium does.
Use a hand or electric pump for latex. Foil balloons with a self-sealing valve fill with a drinking straw or a narrow pump nozzle; the guide to inflating foil balloons without helium walks through it step by step, including how to hang them so they look like they’re floating.
Which is better for garlands, centerpieces and gifts?
Garlands and arches: latex
Garlands need volume, and only latex gives you dozens of balloons in coordinated colors. A 30-pack of 12-inch balloons like the blue polka dot latex balloons fills a few feet of garland; the balloon arch strip guide has per-foot counts.
Focal points and messages: foil
One large foil shape draws the eye in a way a cluster of rounds can’t. The 30 x 24 inch smiley face birthday balloon has a self-sealing valve and comes with a 33 ft ribbon, and the 22.4 x 14.5 inch birthday cake foil balloon works as a cake-table or gift accent. Both float only with helium; filled with air, they hang or tape to a wall.
Mixed displays
A common approach is a latex garland for color and one or two foil shapes for the message. Attach foil pieces to the garland with glue dots or a ribbon tie, and place the main shape at eye level, slightly off center, where it shows up in photos.
Quick picks by situation
If you’re still undecided, match the balloon to the job. These are general pairings, not hard rules:
| Situation | Choose | Why |
|---|---|---|
| Garland, arch or wall of color | Latex, air-filled | Volume in many sizes and colors; no helium to lose |
| Floating bouquet for an afternoon party | Latex with helium, filled the same day | Floats long enough for a few hours of celebrating |
| Balloons filled the night before | Foil with helium | Holds lift for days instead of hours |
| Message, number or character shape | Foil | Fixed shapes and printed messages stay crisp |
| Guest with a latex allergy | Foil only | No natural rubber in the room |
| Hot porch or patio | Air-filled latex in shade, or foil filled to about 80% | Leaves room for the gas to expand as it warms |
For helium bouquets of either type, tie the ribbons to a weight heavy enough that a breeze or a curious child can’t carry it off, and keep the bouquet indoors when you can.
Outdoors: sun, heat and wind
Latex oxidizes in direct sunlight and turns cloudy within hours; dark colors also absorb heat and pop more readily. Foil reflects sun but the gas inside expands as it warms, so a balloon filled tight in a cool room can split a seam on a hot porch. That’s why foil balloon instructions commonly say to stop at about 80 to 90 percent full rather than drum-tight.
Wind is hard on both. Anchor every balloon, bring displays inside in rough weather, and never release balloons outdoors. Helium-filled foil balloons in particular should always be tied to a weight, because a metallic balloon that drifts into overhead power lines can short them and cause an outage.
Reusing and storing foil balloons
Foil balloons with a self-sealing valve can be emptied and saved. Slide a straw into the valve past the narrow neck so the inner flap opens, then gently press the air out from the far end toward the valve. Store the balloon flat, without sharp folds, in a folder or box. Avoid creasing printed areas; repeated hard folds can crack the metallic layer and create slow leaks. Latex balloons can’t be reused once tied.
Safety notes for both types
- Latex allergy: latex balloons contain natural rubber. If a guest has a latex allergy, decorate with foil and keep latex out of the room.
- Young children: uninflated balloons and broken pieces are a choking hazard. Standard US balloon warnings refer to children under 8; pick up pieces of popped balloons right away.
- Ribbons: trim long ribbon tails around cribs and play areas for babies and toddlers.
- Power lines: keep foil balloons weighted outdoors and well away from overhead lines.
For quantities across a whole party, from balloons to banner length, try the party supply calculator.
Frequently asked questions
Do foil balloons float with regular air?
No. Air is heavier than helium, so an air-filled foil balloon sinks just like an air-filled latex one. Fill it with air when you plan to hang it, tape it to a wall, tie it to a chair or mount it on a stick.
Should I fill latex balloons with helium the night before a party?
Not if they're untreated. An 11 to 12 inch latex balloon typically floats for about 8 to 12 hours, so overnight filling can leave droopy balloons by party time. Fill latex the same day, or use foil balloons for anything that needs to float overnight.
Are foil balloons latex-free?
Foil balloons are made from metallized plastic film rather than natural rubber, which is why they're the usual choice when someone has a latex allergy. If the allergy is severe, also keep latex balloons and latex gloves out of the room during setup.
Why did my foil balloon shrink overnight?
Usually the room got colder. Helium contracts in the cold, so the balloon looks soft and wrinkled, then fills out again as it warms. If it stays soft in a warm room, the valve may not have sealed fully or there's a small leak at a seam.
Are self-sealing balloons the same as self-inflating balloons?
No. A self-sealing valve closes itself after you pull out the straw or nozzle, so you don't tie a knot or use a heat sealer. You still have to inflate the balloon with air or helium.
Can you reuse latex balloons?
Not in practice. Once a latex balloon has been stretched and knotted, it doesn't refill evenly and the knot is hard to undo without tearing the neck. Foil balloons with valves are the reusable option.
