Yo-yo string is usually one long strand, that goes down from the finger, loops around the axle (except offstring) and goes back up to the finger. Between the axle and the finger the two ends of the strand are twisted together (note that some manufacturers offer 'left handed' string that is twisted the other way). At the finger end there is usually a slip knot.
Yo-yo string usually comes in four different materials.
- Cotton - The traditional material.
- Slick or 50/50- a blend of 50% cotton and 50% polyester or nylon. These strings are a little more flexible than cotton, slightly heavier (if you can call a yo-yo string heavy) and glide better on fixed axle yo-yos. They are also more durable than cotton strings.
- Rayon - yet another synthetic material in yo-yo string. It has a soapy feel, much like Polyester, however is a little more rigid. It is the longest lasting type of string due to the natural durability of the fiber. An aftermarket synthetic material.
- Nylon - First introduced in Bungee Strings. Almost always has a soapy feel. Dozens of varieties in feel, play, and durability due to the nature of the fiber. An aftermarket synthetic material.
To someone who is new to the sport of yo-yoing, the type of string used may seem a minor detail. However depending on what kind of yo-yo you use, and most of all, what kind of tricks you do, these things actually do matter.
Synthetic strings generally last longer, while cotton will break faster. Cotton is also a bit rough on the skin, and synthetic materials generally have a smooth soapy feeling.
Synthetic materials are a newer introduction in yo-yo string, pioneered by string makers like YoYoFargo and Paul Wallace. Synthetic materials can be spun, and then have their properties changed by using weak to mild plasticizers. They are however, more expensive due to availability of the string, and the fact that they are generally spun by hand. A great example of synthetic string is G-String by Paul Wallace. Polyester does not make a good yoyo string because it doesnt allow the roll as well as the traditional cotton does.
The thickness of the string makes a big difference to yo-yo performance and so a number of thicknesses of string are available. A few years back there was no real terminology for this, there was just ordinary string, and there was Tom Kuhn string which was slightly thinner. These days there are three thicknesses of string available, 8 (4*2), 6 (3*2) and 9 (3*3). Type 8 is used for the most responsive yo-yos, and types 6 and 9 are favoured by players who prefer unresponsive yo-yos. The numbers in brackets refers to the number of strands in the yo-yo string. For example, type 8 consists of four strands each composed of two smaller strands of string. So if you see String described as slick six, this means it's a string made of cotton and polyester made of two strands consisting of three smaller strands.
The string that comes with most yo-yos as 'standard' string is usually type eight.
Yo-yo string is typically one metre in length, although longer strings are available. New string is shorter and the string stretches as it is used. Some players (such as Tomonari Ishiguro) prefer to stretch the string by gently pulling so that the string doesn't stretch further during play. Particularly long strings are favoured by some offstring players, as the yo-yo doesn't hang on the end of the string in offstring play.
How often should you replace the string on your yo-yo? You should usually replace it when it looks a bit frayed; frayed string always runs the risk of breaking. With the advent of transaxle yo-yos the string was subjected to far less friction and thus the risk of a string breaking (due to friction) was greatly reduced.
However a piece of string still wears out. It loses its elasticity and flexibility. The latter is due to felting: the fluffy surface of one strand tangles with the fluff of the other strand to produce one thick piece of string and even though the string feels a bit smoother, it is far less flexible. The loss in elasticity is due to the constant stretching of the string when it gets rolled up inside the yo-yo under high tension.
When putting your yo-yos away you can prolong the life of your string by storing it unwound. As a simple test, you can take a new string, wind it tightly into the yo-yo and then let the yo-yo rest for a few days. The string will not be so elastic anymore and it will also not lie straight.
Stringing your yo-yo
The most common way to put the string on to the yo-yo is to open the loop at the end and put the strand around the axle. With a fixed axle yo-yo this is the only way that allows the yo-yo to sleep. This referred to as 'single looped' as there is only one loop of string around the axle.
In some circumstances you may want to double loop your string around the axle. With a fixed axle this prevents the yo-yo from sleeping. With the early ball bearing yo-yos like the Tom Kuhn Silver Bullet 2 before the advent of Response Systems you had to do this in order to create a small amount of friction at the gap sides to make the yo-yo return.