Crease Pattern FAQ

Post by **origami_8** » December 22nd, 2006, 9:17 pm

Since the question about how to begin with crease patterns (CPs) arises that often I decided to create a sticky post about it.

First of all, what exactly is a CP?

A CP is like the name indicates a drawn pattern of creases, that shows the main creases you need to create a (flat foldable) base from where on you need to add more details until you end up with the finished model.
Sometimes only one half of a symmetrical CP is shown and the other half shows how to get some important reference points.
To fold after CPs you need a lot of patience and experience. If you're a beginner with Origami first learn to fold after diagrams before starting with CPs.

When beginning with crease patterns make sure to begin with the easy ones. Like with everything else only praxis can make you better and sometimes folding something else and then trying again will get you further than trying the same model again and again without success.

A special case of CPs are boxpleated ones. You can identify them at once by the large amount of fan-like horizontal and vertical creases only divided by 45° angled diagonals. When beginning with this kind of CPs first fold in half along the symmetrie line and continue with making waterbomb bases on the 45° lines. After sinking everything in and out you will need to open out parts of the CP to add the remaining creases in the right directions.

Topics about CPs on this Forum that contain useful informations can be found here and here.

The best website guides when beginning with CPs can be found here and here.
Look here to find a lot of boxpleated CPs.

Useful programs for creating and solving CPs are Robert J. Langs Treemaker and Reference Finder that can be downloaded from his website.

Look here for informations on vertex assigned CPs.

Post by **Daydreamer** » February 5th, 2007, 8:10 pm

I've started a guide on how to fold box pleated CPs.

The first part explains how to read and understand a box pleated CP.
(This part has been updated on 2007/02/05. If you downloaded an earlier version you should get the new one.)

The second part explains the precreasing process including instructions how to get different paper divisions.

In the third part the collapsing process starts. You will also find an explanation with examples of Elias stretches in this part.

The fourth part continues the collapsing process with a rather extreme Elias stretch.

The guide can be found on the Origami Austria homepage in the articles section.

More parts will be available as soon as I finish them.

Brimstone · Post by **Brimstone** » January 21st, 2008, 2:47 am

I am going to summarize here what I've said on several posts regarding CP's:

One thing that is important to understand and that many people don't seem to know (at one time I thought the same), is that the CP usually takes you to the base of the model, but to accomplish the finished model, you still have to (in many cases) do a lot of folding based on your own experience and imagination. Take the case of Miyajima's CP's. They are not very difficult, but to get from the base (the intended step of the CP) to the Finished model it can take you 100 + steps.

There is no single answer for the question of which creases are mountains and which ones are valleys. Usually the creases right next to the border of the paper (considering you are solving the CP color side up), will be mountains, there might be exceptions to this rule, but it is so 99 % of the times. Color change could contradict this statement, but usually CP's are done for the base and not the finished model, so they will still be mountain.

There are plenty of CP's all over the internet, to name just a few:
Jason Ku: http://scripts.mit.edu/~jasonku/index.php
Noboru Miyajima: http://www.h5.dion.ne.jp/~origami/e/gallery.html
Satoshi Kamiya: http://www.folders.jp/
Hideo Komatsu has some difficult ones too: http://www.origami.gr.jp/~komatsu/gallery/index.html
And Meguro Toshiyuki has apage with links to CP's http://www.geocities.co.jp/HeartLand-Oa ... nhyou.html

And for some easy ones, some of the models on this page http://isuzuginnosuke.hp.infoseek.co.jp ... ri-top.htm are easy. Check the model and if it looks simple, then the CP might be simple.

Washi · Post by **Washi** » September 30th, 2009, 10:43 pm

How do we know what is a mountain fold or valley fold?

WhisperPuffin · Post by **WhisperPuffin** » October 1st, 2009, 8:48 am

Look at a place were creases meet at the edge of the paper in the crease pattern. Generally if you start with coloured side up, the creases closest to the edge connecting to that point are mountains unless the model has a colour change. then the next set inwards from the edge are valleys. And so on.

From there the creases that cannot be solved I would crease either way then reverse the crease, and when you collapse they will "choose" which direction they should go.

When you get more experienced, you'll know which are which because you'll know how certain crease structures collapse and what valley/mountain configuration they employ.

Hope I helped!

insaneorigami · Post by **insaneorigami** » October 2nd, 2009, 7:11 pm

Like WhisperPuffin said, the outermost creases are generally mountains. You only really need to know one or two creases, and those should let you know what the entire rest of the model is. This is especially useful for box-pleated designs.

Pixion · Post by **Pixion** » January 9th, 2010, 3:59 am

-Are CPs by definition flat foldable (so one can use the M-V=2 rule, or Kawasaki theorem to figure out some missing fold directions)

-Why do publishers of CP not indicate the direction of the folds? Do they want to keep others from 'easily' folding the base and keep CPs a black art (literally...)? Robert Lang once indicated it had a technical origin, but I think this comment was made in the dark ages of matrix printers and monochrome screens.

Why not just color code it for dense CPs and dash/dot it for the not so dense CPs. Not indicating fold direction to me sounds like providing a city map without street names...

Post by **origami_8** » January 9th, 2010, 11:34 am

Most CPs are flat foldable bases, but not all of them.
Adding the mountain valley orientation by using different shades of grey or colours would be possible but isn't really necessary. In many cases there is only one possible way to fold it non the less. Adding dashed or dotted lines would make everything confusing. After all CPs are no full diagrams but some kind of accommodation from the designer to the folders. You should rather be glad that they publish them than to demand further details.

Pixion · Post by **Pixion** » January 9th, 2010, 4:05 pm

Origami_8,

Thanks for your remarks.

So, is it fair to say that figuring out fold direction is really the easiest part in folding from a CP? I understand there is only one way, but depending on the number of creases, it may be one in a million!

I kindly want to note that I am not demanding anything and indeed are grateful that some artists share their art in the form of diagrams or CPs.

Jonnycakes · Post by **Jonnycakes** » January 9th, 2010, 10:42 pm

There are common structures of creases that pop up in CPs all the time, and there is a standard way to assign M/V creases to them. Once you can recognize these structures/patterns, most crease directions can be figured out fairly easily.

Pixion · Post by **Pixion** » January 10th, 2010, 1:20 am

Johnny,

Thanks. I guess I will have to get into CPs a bit more to see through the patterns. Maybe I compile a list of those common elements you mentioned and their 'local CP' (waterbomb, box pleats, rabbit ear etc.).

Jonnycakes · Post by **Jonnycakes** » January 10th, 2010, 4:13 am

Exactly! Just like a waterbomb or a rabbit has a specific set of M/V creases, other structures do as well. In fact, they are related more than you might think...they follow a certain set of mathematical principles in order to possibly fold flat: http://en.wikipedia.org/wiki/Mathematic ... er_folding

pandaraoke · Post by **pandaraoke** » January 21st, 2010, 8:07 pm

WOW! Thank you thank you! It'll take a while for me to go through the information just in this post alone!!!
So excited about folding!

I have a feeling I'm going to fold until my fingers BLEED! hahaha!

fold-it-all · Post by **fold-it-all** » February 3rd, 2010, 3:17 am

I may not have folded till I bled, but I have folded myself to sleep, in class!I guess you can call it ironic, I have never gotten a paper cut in all of the 8 years I've been folding.

hobbestheprince · Post by **hobbestheprince** » February 26th, 2010, 4:27 am

I read somewhere that the largest lines are often most important in crease patterns, so those should be folded first. Is this true, and does it apply to box pleated designs as well?