Many origami models start by folding the paper in half, either corner to corner or edge to edge. Immediately, we’re folding with references. A “reference” in origami is an identifiable landmark that can be used as a guide for the next step. It could be an edge, a corner, a flap, a crease, an eyeballed measurement (I’ve gotten much better at eyeballing thirds over the years, though there are ways to measure them out exactly using a series of creases), or a combination of these elements, such as the intersection of two creases or the point where a crease meets an edge.
There are a few reasons I tend to seek out reference points when I design. First, it makes the sequence easily repeatable. If I need to mass produce the model, identifying references for each step keeps the output consistent. Second, folding with references can make a model look generally cleaner. Consistency and repetition beget precision. Plus, while working with references doesn’t always mean the model will be built on specific mathematical proportions, there are certainly some proportions that make a structure more aesthetically pleasing.
Third, I’m able to remember the folding sequence more easily. Rather than memorize the entire process from open square to finished model, I allow the sight of each completed step to remind me what comes next. Some memorization techniques, including some of the ones used by memory athletes, are about chunking smaller portions of the entirety of the information to be memorized and stringing those chunks together. For example, folding a Crane is easier to remember when you know the first part of the sequence is to fold a Bird Base. If you know how to fold a Bird Base, you’ve already memorized most of the sequence! That’s one reason it’s useful to learn the common origami bases.
My other major reason for identifying references is it makes the model easier to teach. I’ll play devil’s advocate to this in a future challenge, but I’ve found it makes for clearer teacher-student communication when the teacher can point out specific targets to aim for. Beginner students appreciate the clarity of directive and advanced students appreciate the opportunity for precision. I like challenging my students who are developing their own models to find a reference for each step because it asks them to examine their model more closely and perhaps revise it a few times, develop their eye as a folder, and instills generosity with the notion that they’ll be able to more easily teach and share their model. I encourage new origami teachers to use as many references as possible in their teaching script, even to find references in models that don’t traditionally use them.
So then how do you determine references? First, check the model at each step for any landmarks that already exist. Some of these may be obvious – if you’re bisecting an angle, the boundaries of the area are probably defined, either by edges, creases, or both (think of the raw edges and center crease used to make a Kite Base). Corners and intersections are also common references. Sometimes I’ll add steps to the sequence to install a crease that later becomes a reference. The neck of my Flying Goose, for example. is adjusted by Pleat Folding it into the body. You could eyeball the Pleat Fold to find the length you like, but since it’s a simple model I teach with, I’ve figured out a series of creases I can add that work for references. There’s no specific mathematical/creative reason for the length I’ve chosen except that I like how it looks and I like that the sequence is repeatable, memorable, and teachable.
I’ve also extended folds beyond what I immediately need them for in order to create a crease I’ll use later on. For example, if I’m designing a model from a Fish Base, I might make sure that one does four complete Kite Folds before collapsing into the Fish Base and use the creases that go beyond what’s necessary for the Rabbit-Ear Fold as a reference. In this Rat model, which starts with a Dinosaur Base, I fold complete Kite Folds before the Rabbit-Ear Fold and use the visible crease for an Inside Reverse Fold later.
If I can’t find a reference that involves directly aligning points, edges, creases, etc.I might look for references that I can eyeball. For my Simple Skunk, I create the ears by folding a third of the flap in. There might be a way to precisely measure the angle, but it’s neither structurally imperative for that measurement to be exact nor worth the added effort in a model intended to be simple. Eyeballing parallel or perpendicular lines can also be useful points of reference. At one point in my Dachshund sequence, I eyeball folding a flap so one of its edges is parallel to a crease on the other side of the model.
It’s not that every step in origami sequences need or are better with references. I think it’s equally fruitful to develop the ability to sculpt and shape models intuitively. More on that later. This challenge asks the artist to be specific in their design process and hopefully develop their models to the point where they can teach and share them with others.