A flying lantern (also called a sky lantern) is a lightweight paper balloon lifted by the heat of a small flame. You can build one with just three components: a paper envelope, a bamboo frame, and a fuel source. The whole project takes about 30 to 45 minutes once you have your materials ready.
Before you build one, know that sky lanterns are banned in several U.S. states, including Illinois, and restricted in many other regions due to fire risk. Check your local regulations before launching anything.
How a Sky Lantern Actually Works
The principle is the same as a hot air balloon. The flame heats the air inside the paper envelope, making it less dense than the cooler air outside. Once the lifting force of that lighter air exceeds the total weight of the lantern, it rises. For a traditionally shaped lantern, the air inside needs to reach roughly 83 to 99°C (about 181 to 210°F), depending on the lantern’s shape and weight. Lighter lanterns with more internal volume lift off at lower temperatures.
This means every design decision you make matters. A lantern that’s too heavy, too small, or made from thick paper won’t generate enough lift. The goal is to maximize the air volume inside the envelope while keeping the total weight as low as possible. Research on different lantern shapes shows that the mass-to-volume ratio needs to stay below roughly 0.2 kg per cubic meter for reliable flight in normal conditions.
Materials You Need
The traditional materials are rice paper, thin bamboo strips, and a small piece of wax-soaked cloth or cotton for fuel. These same materials have been used for centuries, and testing shows they perform just as well as modern synthetic versions.
- Paper envelope: Tissue paper or rice paper works best. You need 4 to 6 large sheets (roughly 50 × 70 cm each). Tissue paper is lighter and easier to find. Avoid anything heavier than wrapping-grade paper.
- Frame: Thin bamboo skewers or strips, bent into a circle about 25 to 30 cm in diameter. Bamboo is ideal because it’s strong, flexible, and very light. You can also use thin wooden dowels or stiff cardboard strips.
- Fuel cell: A small square of cotton cloth (about 5 × 5 cm) soaked in melted candle wax, or a small birthday candle. The fuel needs to burn steadily for several minutes without dripping.
- Adhesive: White school glue or a glue stick. Keep it minimal to avoid adding unnecessary weight.
- Thin wire or string: A short piece to suspend the fuel cell from the bamboo ring. Thin cotton thread is a biodegradable option.
Building the Paper Envelope
The envelope is basically a tall bag, open at the bottom and closed at the top. The simplest shape to build is an elongated cylinder with a rounded top, similar to a pill capsule.
Take four sheets of tissue paper and lay them flat. Cut each sheet into a panel shaped like a long, rounded petal: wide in the middle, tapering to a point at the top, and straight across the bottom edge. Each panel should be about 60 to 70 cm tall and roughly 40 cm across at the widest point. Glue the long edges of the panels together, one by one, to form a balloon shape. Overlap each seam by about 1 cm and press flat. Make sure the seams are airtight. Any gaps will let hot air escape and reduce your lift.
Once all four panels are joined, you’ll have an open-bottomed bag. The bottom opening should be roughly the same diameter as your bamboo frame ring, about 25 to 30 cm across. Hold it up and check for holes or weak seams. Patch anything that looks thin with a small piece of tissue paper and glue.
Making the Bamboo Frame
The frame serves two purposes: it holds the bottom of the envelope open so hot air can fill it, and it provides a place to attach the fuel source. Soak two bamboo skewers in warm water for 15 to 20 minutes to make them pliable. Bend each one into a half-circle and let them dry slightly. Cross them at right angles to form an X shape and tie or glue the intersection point. Then bend the four ends into a circular ring and secure them.
The finished frame should be a circle with two crossed supports running through the middle, like crosshairs. Keep it as light as possible. Thinner bamboo strips are better than thick ones, even if you need to reinforce the joints with a drop of glue.
Attaching the Fuel Cell
Suspend the fuel cell from the center of the crossed bamboo supports, where the two strips intersect. If you’re using wax-soaked cotton, wrap a small piece of thin wire around the cloth and twist the wire around the center joint so the fuel hangs about 2 cm below the frame. If you’re using a small candle, secure it upright at the center point with a drop of melted wax or a small clip of wire.
The flame needs to point upward into the envelope’s interior without touching the paper. Leave at least 10 to 15 cm of clearance between the flame and the nearest paper surface. If your envelope is too short for this, make the frame slightly smaller or trim the fuel cell.
Assembling and Testing
Glue the bottom rim of the paper envelope around the outside of the bamboo ring. Fold the paper edge over the ring by about 1 to 2 cm and press it down firmly. Go all the way around, making sure the paper is attached securely with no gaps. The envelope should hang loosely above the frame like an upside-down bag.
Before lighting anything, hold the lantern upright and check a few things. The paper should hang freely without bunching against the fuel cell. The frame should hold the opening in a clean circle. The whole structure should feel very light. If it feels heavy in your hands, it probably won’t fly. Trim any excess glue, shorten the bamboo, or use thinner paper.
Launching Safely
Sky lanterns are open flames attached to paper, so where and when you launch matters more than the build itself. Only launch in calm conditions with wind speeds below 5 mph (about 8 km/h). Even a light breeze can push a lantern into trees, buildings, or dry brush.
Choose a wide, open area. Stay at least 30 meters from trees and buildings, and at least 100 meters from crop fields, haystacks, or power lines. Have water or a fire extinguisher on hand.
To launch, hold the lantern upright by the frame with the opening facing down. Have a second person light the fuel cell. Keep holding the lantern while the flame heats the air inside. After 30 to 90 seconds, you’ll feel the lantern start to tug upward in your hands. When the pull feels strong and steady, let go gently. Don’t throw it or release it in a gust of wind.
Choosing Biodegradable Materials
Conventional sky lanterns often include metal wire in the frame, which doesn’t break down and poses a serious hazard to wildlife and livestock. Animals can become entangled in wire frames, and metal debris can damage farm equipment. If you’re building your own, stick entirely to bamboo, paperboard, cotton string, and untreated tissue paper. All of these decompose naturally over time. Avoid any metal wire, synthetic string, or plastic components.
Even with biodegradable materials, the lantern still carries a fire risk until the fuel is fully extinguished. A lantern typically stays aloft for 6 to 10 minutes before the fuel burns out and it descends. Where it lands is largely out of your control, which is the core reason many jurisdictions have banned them entirely.
Where Sky Lanterns Are Restricted
Several U.S. states have outright bans on releasing sky lanterns. Illinois, for example, classified them as prohibited consumer fireworks in 2013. Many other states regulate them under existing fire codes or open-burning laws. In the UK, Australia, and parts of Asia, local bans are common near agricultural areas and airports.
The FAA does not currently regulate sky lanterns directly at the federal level, but launching near airports or in controlled airspace can still create hazards and legal liability. If you’re unsure about your area, check with your local fire marshal’s office before launching. Some locations allow sky lanterns on private property with landowner permission, while others prohibit them under any circumstances.