A good gaming mouse cable has to be good at a couple of things. The four most important factors in my opinion are: flexibility, slickness, low weight and durability. Spoiler alert: a gaming mouse cable should not be braided.
In the following I will explain why these four attributes are important and show what we did to address them.
A good gaming mouse cable should not be too rigid or stiff. The reason is simple: a rigid cable does not move easily and thus you have to exert more force to move a mouse with a rigid cable, as compared to a mouse with a flexible cable. Depending on the direction your cable points to and the direction of your mouse movement you can feel the cables resistance. This can be very distracting while gaming.
With a very light gaming mouse the effects of a rigid cable become more obvious: when you only need a small amount of force to move your very light mouse around, a rigid cable feels much more resistant than if it were on a heavy mouse.
A cable should not be too flexible and limp though. Imagine your mouse with a piece of dental floss attached instead of a cable. The dental floss is so limp that every time you would move your mouse forward the dental floss most likely would get in the way of your mouse. Or put another way: a mouse cable has to be stiff enough so that when you move your mouse forward, the cable moves with it.
Note that most gaming mouse cables are so ridiculously rigid that they will never block your mouse movement. Lack of flexibility is the biggest weakness in most gaming mouse cables.
So how do you make a cable flexible? The two most important factors are the cable jacket and the copper conductors.
Cable jacket materials
When it comes to cable jacket materials there are a bunch to choose from. They all have their advantages and disadvantages.
Take polyvinyl chloride (PVC) for example: PVC jackets in itself would not be very flexible. Which is why plasticizers like phthalates are commonly used to make them softer. The problem with phthalates is that they leach over time, meaning your cable becomes less flexible. Also phthalates could be bad for your health. On Wikipedia it says:
An endocrine disruptor is a substance that interferes with the normal hormonal mechanisms that allow a biological organism to interact with its environment. In the scientific community, phthalates are broadly classified as endocrine disruptors; while many scientific studies indicate the likelihood that phthalates behave as endocrine disruptors in human beings.
Next there are fluoropolymer jackets like for example polytetrafluorethylen (PTFE). A PTFE jacket would make for the slickest cable jacket there is. However the flexibility of a PTFE jacket is poor (unless you make them extremely thin-walled, which is hard to do on a gaming mouse cable which by nature has a relatively large diameter). Due to their high density a PTFE jacket also would be relatively heavy.
Then there is silicone. A silicone jacket would be very flexible. Yet silicone has a tacky surface and is not that great when it comes to durability.
In the search for the optimal gaming mouse jacket material we ended up with a material called polyurethane (PUR). A jacket made of PUR not only can be made very flexible without the use of phthalates. It also fulfills the other requirements for a good gaming mouse cable: it can be made with a very slick surface that will not drag on your mouse pad. PUR is also relatively low in weight. And finally PUR is extremely durable.
As you may know a typical USB cable has four conductors inside. Each of these conductors consists of copper wires that are twisted together. In a standard gaming mouse cable one conductor consists of seven pretty thick copper wires with a diameter of 0.12 millimeters each.
In our cable we use 19 very fine wires per conductor with a diameter of just 0.05 millimeters each. Using 19 fine wires instead of 7 thick ones has two advantages. First, they make the cable more flexible. Think of it this way: bending two wires that together are as thick as one thick wire requires less force than trying to bend that one thick wire.
Second, they make the cable more durable when subjected to bending, something that is called flex life (or quintessentially German: Biegewechselfestigkeit). Let me be clear though: every time you bend a cable it will reduce the longevity of your cable by a tiny bit. Fine copper strands lessen the negative effect bending has, but they do not completely negate it. So be nice to your cables.
This is the point where I bash on braided mouse cables. A good gaming mouse cable needs to be slick, so it will glide over your mouse pad without you noticing it. A braided mouse cable is the opposite of slick. It has a rough surface that scratches on surfaces, which is distracting. And looking at how braided mouse cables are made the reason why they are not slick becomes obvious: The braid of a cable is most commonly made of lots of nylon fibers that are woven over each other. A woven surface is not uniform, which increases the probability for it to get caught on things, like your cloth mouse pad. But even on a hard mouse pad you can feel a braided cable getting caught for example when you move your cable over the edge of your mouse pad.
Over time some of the nylon fibers in the braid will become loose or otherwise damaged, increasing the surface area of the braided cable which in turn increases the probability of the cable becoming caught.
A braided cable has another big disadvantage: they are hard to clean. Say there is a sticky spot on your gaming mouse cable. With a normal cable you can just wipe it off. But with a braided cable this is not that easy. Think of red wine on a glass table versus red wine on a carpet. You have to be very careful when cleaning a braided cable else you will cause micro tears in the Nylon fibers, which make the cable even more rough. And the more careful you clean, the higher the chances that you will not be able to remove all the dirt.
How come braided cables are so popular then? They look cool.
A good gaming mouse has to be as light as possible. Thus its cable has to be light as well. We achieve this by using very fine conductors, thin conductor insulation as well as a thin cable jacket. This results in a very small diameter for a gaming mouse cable: just 2.5 millimeters. Our cable weighs just 8 grams per meter.
A cable has to have a certain degree of durability. It does not matter how flexible, slick or light a cable is, when it breaks after only a few months of use. This makes for a difficult optimization problem: take the flexibility or weight of a cable for example. One way to achieve a flexible cable is to use a thin jacket. However a thin jacket also results in less durability. And as already mentioned a very thick jacket would be very rigid and very heavy. There is a trade-off between flexibility and durability.
PUR is incredibly durable jacket material when compared to PVC or silicone. Not only is PUR extremely tough, it also has excellent flex life as well as resistance for chemical, water and abrasion resistance. In fact our cable jacket is so durable, that we had difficulties finding an insulation stripper that could properly remove the jacket. Therefore by using PUR for the cable jacket we can get away with a relatively thin walled jacked, retaining low weight and flexibility. As already mentioned having conductors with lots of fine strands instead of conductors with few and thick strands also helps with durability.
Additionally there are a bunch of aramid fibers in the middle of our cable. Aramid is the high-performance plastic that bullet-proof vests are made of. These aramid fibers protect against strong pulls and reduce the abrasion between the four conductors.