Metric units are more direct. When paper “weight” is described in grams per square meter, this removes confusion, but we are probably stuck with knowing and using at least a few different systems for a while.
Only simple, large models can be folded from heavy papers. When you fold the same design from different weights of papers with the same area, those from heavier papers will glide farther, but are less likely to look neat because of bunching caused by the increased thickness. When you lift an airplane and launch it, your arm is imparting a force on the mass of the plane. Those folded from heavier papers have greater mass, but essentially the same area and resistance to air molecules. Other variables being equal, increased mass translates to increased potential energy, and greater distance.
Foldability
How well does the paper take a crease? How many times can the paper be folded back and forth before it splits or cracks? How long does that crease stay crisp? Many papers today are coated with plastic, paint, clay, varnish, wax or even silicone. Some are fused to metal or plastic films. Heavily coated papers and foils are unforgiving of poor technique, so it is important to choose papers that fit your folding skills. At the very least, it is fun and instructive to test an origami airplane on many kinds of papers. This is when the paper is your best teacher.
Rigidity
Rigid paper planes are generally more efficient and fly better than floppy planes. The rigidity can come from the weight and size of the paper, but also the folding method. Compare a paper towel to a sheet of letter paper. Each was formulated and manufactured differently to best suit a particular need. A soft paper towel does not make a good paper airplane: it would be too floppy. However, a paper plane that is folded from a very large sheet of office paper, say four times its typical size, could be so heavy, that the shape of the flaps and wings would distort.
Moisture in the air changes from day to day and also affects paper’s rigidity. On very humid days, you may have noticed that fins flutter and wings droop—this change of shape affects motion. As a deformation propagates along the surface, it results in extra wind resistance and unwanted drag. Energy expended to flex the structure is energy drained from the momentum (forward path of force), shortening or even stalling a flight. Unequal distortions to wing or fin can also result in an erratic path. Using slightly smaller sheets of paper can improve rigidity, as can choosing models that have multi-layered wings with several folded edges.
Special planes intended for photography or display often benefit from the use of crisp tracing paper, which really shows off the intricate folds and precise workmanship.
Rigid wings of balsa or from composites of paper card will always perform better than pure origami planes. Nevertheless, origami airplanes can produce some impressive and very satisfying performances.
Aesthetics Impact Performance
Color pigments, printing inks, and toners on the paper may have a small, but measurable impact on a paper airplane’s mass (and therefore density), surface roughness and symmetry. Besides these technical aspects, the aesthetics of a paper airplane’s appearance may influence the crowd and psych-out the competition. Do drivers of bright red cars receive more speeding tickets? Does the car’s color somehow motivate the driver to hit the gas pedal harder? Do people who are more likely to speed select car colors of the more aggressive hues? Use plain white paper if you subscribe to the maxims “Beauty is only skin-deep,” or “Don’t judge a book by its cover.” This lets you appreciate the elegance of the plane’s lines and geometry. Aesthetics can also be a function of age and culture, so you must decide how to play this card.
Putting It All Together
Paper selection depends upon why you are folding the model. If you are just practicing, use anything available. If you have plenty of used copier paper handy in a recycle bin, begin by learning the models that work well from that format. If you are supplying the paper for an airplane competition, a ream of 20-pound office paper is readily available and inexpensive, so that is what most people use. If a local printing company will donate the paper, ask for 50-pound offset, but don’t be fussy. Thank them profusely, even if they give you misprints. (There are plenty of sponsorship opportunities here.)
When folding paper airplane models for display or photography, we sometimes prefer to fold thin, crisp, white tracing paper with a hard surface finish (this stock is translucent, which shows off the interesting lines of internal folds). These models may not fly as well because the paper is light. Although the creases look sharp, they are also weak. One final note: terms such as “bond,” “offset” or “letter” paper are generic. You should expect quality to vary between different brands, and even paper formulations of the same brand can be changed from time to time. Test, test, test!
Testing Papers
Trial and error is a good teacher, but using the scientific method will help you to organize your investigations and better evaluate your findings. The following is a simple experiment to test papers against airplane designs.
1. Choose one design.
2. Fold several versions with the same size, but different types of paper.
3. Fly each and make notes about their performance.
4. If performance correlates with a given characteristic (say, weight), fold more models with even heavier paper, to determine where the performance benefits trail off.
5. Note the weight that gives you the best performance.
6. You can run the tests again with the same design but with a different variable, say square area.
Eventually you will be able to match paper type, size and airplane design to get your best performance. Remember, you are a variable, too!
Now that you know more about paper types and choices, you will be rewarded by being able to make better choices and evaluations, whether at a paper airplane competition or for your own enjoyment.
Fold the same design at different sizes to discover which scale works best for a given plane.
Additional Paper Handling Tips
Here are some additional tips to optimize your folding experience:
• Make sure your hands are clean and dry. Sorry for nagging, but paper can easily absorb oils and moisture from your skin.
• Leave the paper in the packaging. Paper left out of its packaging is subject to damage from a variety of agents.
• Examine both sides of the paper carefully. Some papers have a finished side that is smoother than the other side. Know which side will show when you fold your model. We have color-coded our diagrams to help you: White is the inside of the model and the colored side is the predominant display side of the finished model.
• When using pages from discarded magazine or calendars, or other “trash” papers, make sure the sheet is completely flat and that the corners are square. Trim to remove any ugly wrinkles or bruised edges.
• If you are adding graphics to your paper, be sure to leave enough time for toner to cool, or inks to dry before folding. Incidentally, papers that pass through the heated rollers of toner-based printers and copy machines seem to become crisper and make better planes.
• Planes that sit around for a while will tend to lose the sharpness in their creases, making them sloppy, unbalanced and not airworthy. Always refresh your creases and check symmetry before flight.
Preparing Your Paper
In the following sections we provide several methods for trimming paper to the proportions used in this book. Use a straightedge or ruler, pencil, and scissors or paper cutter, to easily scale your papers, making larger or smaller sheets of each format. You can use any of the numbers, displayed with each of the rectangular icons in this section, as factors to scale or trim