Guide·Origami

How to Read Origami Diagrams (Folds and Symbols)

Once you can read origami diagrams, you can fold almost any model in a book. The whole system rests on two folds and a handful of symbols. Here is how to read the language of origami instructions.

HobbyStack EditorialJune 4, 2026Updated July 13, 20261 min read
Part of the Origami hobby guideSee the full overview — what it involves, what it costs, and how to start.
Key takeaways
  • Nearly all origami is built from two folds: the valley fold (folding toward you) and the mountain fold (folding away from you).
  • Diagrams use standard symbols: dashed lines for valley folds, dash-dot lines for mountain folds, and arrows showing which way to fold.
  • Learn to recognise the arrows: a normal arrow means fold, a looped arrow means fold then unfold, and a hollow arrow often means turn the paper over.
  • Many models begin from a shared starting shape called a "base" (like the square or bird base). Learn a few bases and dozens of models open up.
  • Fold precisely and crease sharply. Neat, accurate creases early make every following step line up, sloppy folds compound into a mess.

The two folds behind everything

Origami looks like it needs countless techniques, but almost every fold is one of just two. A valley fold folds the paper toward you, so the crease forms a valley (a dip) and the paper comes up on both sides, if you unfold it, the crease points down like a V. A mountain fold is the opposite: you fold the paper away from you (behind), forming a ridge like a mountain peak, and unfolded, the crease points up. That is genuinely most of it. Every complex crane, box, or animal is built by combining valley and mountain folds in sequence. So the first thing to internalise is these two, and the fact that a mountain fold is just a valley fold done on the other side of the paper (flip the paper over and a valley becomes a mountain). Master the two folds and you have the vocabulary; the diagrams just tell you where and in what order to make them.

The symbols: lines and arrows

Origami diagrams are a standardised visual language (largely the "Yoshizawa-Randlett" system), so once you learn the symbols, you can follow instructions from almost any book regardless of language. The lines tell you the type of fold: a dashed line means make a valley fold along it, and a dash-dot line (dashes with dots between) means make a mountain fold. Thin solid lines usually show existing creases or edges. The arrows tell you the action: a solid arrow shows the direction to fold the paper; a curved arrow that loops back means fold and then unfold (just to make a crease); a hollow or half arrow often means turn the whole model over; and other arrows indicate things like "push here" or "pull out." Learning to read these lines and arrows is exactly like learning to read music, a little effort up front, and then a whole library of models becomes accessible to you.

Bases, and folding accurately

Two more things make diagrams click. First, bases: many origami models do not start from a plain square but from a common pre-folded shape called a base, such as the "preliminary base," "square base," "bird base," or "waterbomb base." These bases are folding sequences so widely reused that diagrams often just say "begin with a bird base." Learning a handful of the standard bases is enormously efficient, because each one is the starting point for many different models, so a few bases unlock dozens of designs. Second, precision: origami is unforgiving of sloppiness, because every fold references the ones before it. Line edges and corners up exactly, and press each crease firmly (run a fingernail along it) so it is sharp and clean. Accurate early folds mean the later steps line up neatly; rushed, approximate folds accumulate into a crooked, frustrating mess. Fold on a hard flat surface, take your time, and crease sharply, and the diagrams will reward you.

Do a "valley then unfold" (crease) exactly as the looped arrow shows, even though it seems pointless, those pre-creases are guides that make a later, trickier fold fall neatly into place. Skipping the pre-crease steps because they do not obviously change the shape is a common beginner mistake that makes the following folds much harder.

Common questions

How do you read origami diagrams?

Learn the standard symbols. Dashed lines mean a valley fold (fold toward you), dash-dot lines mean a mountain fold (fold away from you), and arrows show the action: a solid arrow is the fold direction, a looped arrow means fold then unfold to make a crease, and a hollow arrow usually means turn the model over. Many models also start from a named "base." Once you know these few symbols, you can follow origami instructions from almost any book, in any language.

What is the difference between a valley fold and a mountain fold?

A valley fold folds the paper toward you, creating a crease that dips like a valley (the paper rises on both sides). A mountain fold folds the paper away from you (behind), creating a crease that peaks like a mountain ridge. They are opposites, and in fact a mountain fold is just a valley fold made from the other side of the paper, flip the sheet over and a valley becomes a mountain. These two folds are the basis of nearly all origami. In diagrams, dashed lines mark valleys and dash-dot lines mark mountains.

What are origami bases?

Bases are common starting shapes, folding sequences reused across many models, such as the preliminary base, square base, bird base, and waterbomb base. Because they are so widely used, diagrams often instruct you to "start with a bird base" rather than showing those folds again. Learning a handful of standard bases is very efficient: each one is the launching point for numerous different models, so mastering a few bases gives you a head start on dozens of designs.

What do the arrows mean in origami instructions?

Arrows show what action to perform. A solid arrow indicates the direction to fold the paper. A curved arrow that loops back on itself means fold and then unfold (creating a crease line only). A hollow or half arrow typically means turn the whole model over. Other specialised arrows indicate actions like pushing a spot inward, pulling paper out, or repeating a step. Alongside the dashed (valley) and dash-dot (mountain) lines, the arrows tell you exactly how to manipulate the paper at each step.

Why do my origami models come out messy?

Usually because of imprecise folding early on, since every fold in origami references the ones before it, small inaccuracies compound into a crooked result. Line up edges and corners exactly before creasing, and press each crease sharply (run a fingernail along it) so it is crisp. Fold on a hard, flat surface and take your time. Also, do not skip the "fold then unfold" pre-crease steps, they are guides that make later folds land correctly. Neat, accurate early folds are what make a clean finished model.
Bottom line

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