Many types of paper are suitable for origami. Traditional origami paper is precut to squares, brightly colored on one side (an essential feature for folds that exploit the two different colors), and is available from many craft sources. On the other hand, it is somewhat expensive, the texture and foldability varies with the manufacturer, sometimes it is not cut very exactly, and it is unavailable in the more esoteric shapes such as triangles or oddly proportioned rectangles. For those models, you will have to cut your own paper, so you might as well buy what's cheap. For general practice and experimentation, you can buy a ream (500 sheets) of regular bond paper for a few dollars; it will last you forever. Other possibilities include wrapping paper (especially the foil-backed kind) and art papers. You should keep an eye out for unusual patterns or textures in paper. Some craft stores sell a fuzzy, light cardboard that makes wonderful soft animals.

As a fold becomes more complex, the tensile properties of the paper assume greater importance. For example, the first fold in this book, the White-faced Mouse, could be folded out of almost anything—tissue, newspaper, sheet metal, you name it. A more complicated fold (such as the Deer) requires a thin, crisp paper for best results. The Cicada is just about impossible to fold from a thick or weak paper. The considerations when choosing a paper are thickness, strength, ability to hold a crease, crispness (how well flat surfaces support themselves) and forgiveness (how much a crease damages the paper). These qualities, however, cover conflicting objectives. A crisp paper gives clean lines to a model but does not lend itself to subtle shaping and gentle curves. Thick paper takes creases better than thin paper, but complicated models, which have many layers of paper in them, will burst at the seams if made from thick paper. Foil-backed paper (wrapping paper) has become very popular for complex folds. It holds creases extremely well, it has moderate tensile strength, and it can be readily shaped. Unfortunately, it has abominable forgiveness—the slightest wrinkle leaves a permanent mark on the surface, and the paper weakens drastically after it has been creased a few times. The shiny, metallic surface is not particularly appealing in many folds, but that problem can be circumvented by folding the metallic side toward the inside of a model. Nevertheless, every model in this book can be folded from foil paper, so you might want to invest in some. It is often sold in stationery stores with wrapping paper. Many art stores also carry it in large single sheets, and you can usually get the thinnest paper there.

Still, only the last few folds in the book require any paper other than ordinary bond. My personal favorite for all-purpose folding is nine-pound manifold, also called “second sheet.’ Its the kind of paper used in multicarbon forms, and is available from office supply stores in a variety of colors, mostly drab pastels. It is the same color on both sides, so you can’t use it for models that use both sides of the paper to achieve two different colors (for example, the White-faced Mouse). It is very inexpensive, and quite versatile. When you cut your own paper, you should be absolutely certain to cut it to the exact proportions you need. Corners should be absolutely square for rectangles, sixty degrees for equilateral triangles, etc. (Don’t count on any of the corners of a rectangle you have bought to be square; paper manufacturers vary greatly.) Origami is an art in which small errors at the beginning are amplified throughout the course of a fold. Starting with a trapezoid instead of a square is almost guaranteed to end unsatisfactorily.

My folds often use oddly proportioned rectangles. I have adopted the convention of specifying a rectangle as “1:x,” where “x” is the length of the long side of the rectangle. To convert this to real dimensions, multiply “x” by the desired short side of the rectangle. For example, suppose the rectangle were specified as “1:2.138,” and you wanted the short side of the rectangle to be 15 cm long. You would multiply 2.138 by 15 cm (preferably on a calculator) to get 32.07 cm; the resulting rectangle should be 15 cm by 32.07 cm. Some of the more common sizes of rectangle are 1:1 (a square), 1:1.414 (European letter paper, also called A4), 1:1.294 (American letter paper, or 8½ by 11 inches) and 1:2.360 (a dollar bill).

As a fold becomes more complex, the tensile properties of the paper assume greater importance. ... A more complicated fold (such as the Deer) requires a thin, crisp paper for best results. ... The considerations when choosing a paper are thickness, strength, ability to hold a crease, crispness (how well flat surfaces support themselves) and forgiveness (how much a crease damages the paper). These qualities, however, cover conflicting objectives. A crisp paper gives clean lines to a model but does not lend itself to subtle shaping and gentle curves. Thick paper takes creases better than thin paper, but complicated models, which have many layers of paper in them, will burst at the seams if made from thick paper. Foil-backed paper (wrapping paper) has become very popular for complex folds. It holds creases extremely well, it has moderate tensile strength, and it can be readily shaped. Unfortunately, it has abominable forgiveness—the slightest wrinkle leaves a permanent mark on the surface, and the paper weakens drastically after it has been creased a few times. The shiny, metallic surface is not particularly appealing in many folds, but that problem can be circumvented by folding the metallic side toward the inside of a model. Nevertheless, every model in this book can be folded from foil paper, so you might want to invest in some. It is often sold in stationery stores with wrapping paper. Many art stores also carry it in large single sheets, and you can usually get the thinnest paper there.

Many types of paper are suitable for origami. Traditional origami paper is precut to squares, brightly colored on one side (an essential feature for folds that exploit the two different colors), and is available from many craft sources. On the other hand, it is somewhat expensive, the texture and foldability varies with the manufacturer, sometimes it is not cut very exactly, and it is unavailable in the more esoteric shapes such as triangles or oddly proportioned rectangles. For those models, you will have to cut your own paper, so you might as well buy what's cheap. For general practice and experimentation, you can buy a ream (500 sheets) of regular bond paper for a few dollars; it will last you forever. Other possibilities include wrapping paper (especially the foil-backed kind) and art papers. You should keep an eye out for unusual patterns or textures in paper. Some craft stores sell a fuzzy, light cardboard that makes wonderful soft animals.

As a fold becomes more complex, the tensile properties of the paper assume greater importance. For example, the first fold in this book, the White-faced Mouse, could be folded out of almost anything—tissue, newspaper, sheet metal, you name it. A more complicated fold (such as the Deer) requires a thin, crisp paper for best results. The Cicada is just about impossible to fold from a thick or weak paper. The considerations when choosing a paper are thickness, strength, ability to hold a crease, crispness (how well flat surfaces support themselves) and forgiveness (how much a crease damages the paper). These qualities, however, cover conflicting objectives. A crisp paper gives clean lines to a model but does not lend itself to subtle shaping and gentle curves. Thick paper takes creases better than thin paper, but complicated models, which have many layers of paper in them, will burst at the seams if made from thick paper. Foil-backed paper (wrapping paper) has become very popular for complex folds. It holds creases extremely well, it has moderate tensile strength, and it can be readily shaped. Unfortunately, it has abominable forgiveness—the slightest wrinkle leaves a permanent mark on the surface, and the paper weakens drastically after it has been creased a few times. The shiny, metallic surface is not particularly appealing in many folds, but that problem can be circumvented by folding the metallic side toward the inside of a model. Nevertheless, every model in this book can be folded from foil paper, so you might want to invest in some. It is often sold in stationery stores with wrapping paper. Many art stores also carry it in large single sheets, and you can usually get the thinnest paper there.

Still, only the last few folds in the book require any paper other than ordinary bond. My personal favorite for all-purpose folding is nine-pound manifold, also called “second sheet.’ Its the kind of paper used in multicarbon forms, and is available from office supply stores in a variety of colors, mostly drab pastels. It is the same color on both sides, so you can’t use it for models that use both sides of the paper to achieve two different colors (for example, the White-faced Mouse). It is very inexpensive, and quite versatile. When you cut your own paper, you should be absolutely certain to cut it to the exact proportions you need. Corners should be absolutely square for rectangles, sixty degrees for equilateral triangles, etc. (Don’t count on any of the corners of a rectangle you have bought to be square; paper manufacturers vary greatly.) Origami is an art in which small errors at the beginning are amplified throughout the course of a fold. Starting with a trapezoid instead of a square is almost guaranteed to end unsatisfactorily.

My folds often use oddly proportioned rectangles. I have adopted the convention of specifying a rectangle as “1:x,” where “x” is the length of the long side of the rectangle. To convert this to real dimensions, multiply “x” by the desired short side of the rectangle. For example, suppose the rectangle were specified as “1:2.138,” and you wanted the short side of the rectangle to be 15 cm long. You would multiply 2.138 by 15 cm (preferably on a calculator) to get 32.07 cm; the resulting rectangle should be 15 cm by 32.07 cm. Some of the more common sizes of rectangle are 1:1 (a square), 1:1.414 (European letter paper, also called A4), 1:1.294 (American letter paper, or 8½ by 11 inches) and 1:2.360 (a dollar bill).