Have you ever been frustrated that despite how tightly you’ve wrapped your tsuka, the ito eventually starts to slip with use?
Well, you’re not alone and you’ve probably tried the usual fix of gluing the ito as you wrap and making a mess or used bulky double sided tape which is also not the greatest solution. Perhaps you tried using some type of awful fly tape like they use in most Chinese production sword shops…ugh, what a nightmare that stuff is! 

Double sided tape can be bulky and glue can ruin the ito if you’re not very careful and fly tape, well, just no…so what is it that will help the wrapped ito from loosening and not drive you crazy during the process?

The answer is Kusune. Kusune is a pine resin pitch that tsukamaki-shi use to make the underside of the ito tacky.
The kusune is typically applied to the end of a stick like this

 

 

 

 

 
This pitch is made from pine sap, oil, and depending on the particular recipe, some other ingredients like charcoal powder could be added. There are different formulas that will produce softer pitch so it works better in the colder weather and another so it doesn’t easily melt in the warmer months. Kusune can also be formulated to be used as a glue to bond items such as a kozuka to a kogatana for instance. 

The raw pine sap (matsuyani) can be either collected from Pine trees or purchased from craft supply stores. In it’s unprocessed state it looks like this

                                                                     

 

Or when cleaned of debris, it can look like this  

 

I’m on my second batch that I made myself and while it works well and I’m happy with the results, I will say that it’s a messy (and smelly) process and not one of my favorite things to do. Definitely something better done outdoors if possible. 

The finished kusune ball is brushed against the underside of a strand of ito, one section at a time as you’re wrapping the tsuka,

leaving a light trace of pitch residue on the fabric
                                                                                                    

which makes it tacky and able to stick better to the surface of the wood edge or shims of the ha and mune sides of the tsuka core. It will also stick better on the hishigami and the samegawa. 

The exact recipe and process of making this sticky product is a pretty closely guarded secret, usually being passed down from teacher to student. Since I have no teacher or master, I have pieced together bits of information I gathered from books and internet to experiment in a lot of trial and error until I was satisfied with my results. 
It really helps my tsukamaki and now that I use it, I don’t know how I managed without it. I have tried alternative products like baseball pine pitch, which was way too sticky, and synthetic glove pitch that was not tacky enough. Basically, there is no suitable substitute that I have found. 

Well, I hope this sheds some light on a solution to your slipping tsukamaki blues :)