Sumitsubo (ink pot) set up and use.

This is one of a series of articles that will describe how to set up and use various Japanese woodworking tools in an effort to show you how they work and how you might be able to include them in your own workshop. If you already own some of the tools included in these articles, then you may find new ways in which you can use them.

When it comes to Japanese tools, there is rarely one ‘right’ way to make them work. While it is often said that you must use xyz tool in a particular, proscribed manner it is more likely a case of that way being one of several ways to use the tool. This is not a hard and fast rule, and if you find that you wish to use a tool in a way that ‘goes against the grain’, then you should go ahead and do it, provided that the method is safe and will not harm the tool.

Setting up and using a sumitsubo traditional style ink line.

Previously, we looked at setting up and using a modern style ink line, and discovered that they are easy to set up, easy to use and can be a handy bit of gear to have in the workshop in certain situations.

But the modern style inkline with automatic line rewinding, sealed ink reservoir, modern materials and clean design didn’t just appear, fully formed and ready to go to work. These modern tools have been available for only a relatively short time, and as you might expect, the predecessor is a much simpler tool but no less useful.


Here we have a Shinwakaba sumitsubo (translation; ink pot). If you have a copy of “Japanese Woodworking Tools” by Toshio Odate, then flip to page 13. Look familiar? I though it might. This particular tool is very well known in Japan, being a fairly basic traditional designed and constructed sumitsubo, and where ‘real’ sumitsubo start. Beyond this tool, the sky is the limit for price and embellishment.

While I say this tool is ‘traditional’, it is mainly so in concept because these tools were usually craftsman made, and ranged from the most basic device to incredibly elaborate objet d’art. As this is a manufactured tool (hand made, but the person who made it does not use it) it is not strictly traditional, but we are splitting hairs here and there’s no need for that.

The basics of the tool are very simple. A reel for holding a string, a method of applying ink to the string and a body to keep it all together.

In the case of the Shinwakaba sumitsubo above, the wooden parts are made of keyaki (Zelkova Serrata, Japanese elm), a wood prized for it’s durability and beauty and comprise of a reel, a body with a place to hold the reel and a large bowl shape to hold the wadding. The metal is steel with a small piece of brass fashioned into a comfortable handle. There is also a small porcelain insert for the string to pass through to reduce wear. The included wadding is a silk cotton, the line is also silk and the bowl has been coated to prevent the wood becoming warped from the ink.

A simple device, and believe me the picture does not do it justice.

But as with many things, there is something to suit all tastes and budgets, which gives us this…

sumitsubo parts

The plastic equivalent, and all the parts laid out to make it tick. Strangely, these plastic versions retain the elaborate ‘carvings’ present on more upscale sumitsubo, but regrettably it doesn’t transfer to the industrial plastic used to construct these things.

The saving grace of these tools is that they are cheap, really cheap and most crafts-persons who own something a little more upscale usually own one of these beasts too, simply because they are so cheap and allow a little freedom.

#1 is obviously the body of the sumitsubo. Made of plastic with a simple steel pin axle and no winding handle.

#2 is silk wadding, used to ink the line as it passes through.

#3, the karuko (translation; carrier or porter) that is included with this sumitsubo, also plastic with a steel pin.

#4, silk line for strength. Available in various sizes, this is #17 size.

#5, ink chips. These are included with the wadding on occasion.

(The wadding shown is not the wadding I used, preferring to use simple cotton because I plan to use this sumitsubo for coloured ink later).

When you buy wadding, it is available with little ‘extras’ inside. Not always, but often enough. The one shown above includes a small bag on ink chips. A different brand includes small permeable bags to help keep the wadding under control.

Karuko are available in different sizes and styles, depending on what you require. From the simple shown above, wooden bodied and even one with a large spike for being driven into concrete.

So, we have all the parts, what do we do with them?

Sumitsubo set-up.

Firstly, we need to thread the line through the body and fix it to the reel. Unroll the line and run it through the hole in the outside and then through the hole between the bowl and reel and tie the line to the reel. Wind the line into the reel applying a little drag to the line to help keep it neat on the reel, and tie the loose end to the karuko.

sumi threaded

karuko knot

Next, take the wadding (about 3-4 eggs worth, loose) and dampen it with water (I didn’t, my mistake!) and insert half of it into the bowl under the line. We want it damp, not wet.

sumi half wadding

Place some dry ink chips on the wadding,maybe half a golf ball or so. I was a little heavy handed here I think, but it won’t go to waste.

sumi inked wadding

Then cover the line with the remaining wadding and tuck it under the sides so it will stay put.

sumi assembled

Next, we need to coax the ink to soak into the wadding so the line can be inked as it runs through. This can be done with just dry ink, but some liquid ink does help somewhat. The ink chips will slowly dissolve, meaning that you will not need to add ink to the sumitsubo very often. If you wish to use the ink line now, you will need to add liquid ink.

(You can make this using chips with a little water and crunching up the chips until they are all dissolved. Start with 1:1 by volume of chips and clean water.)

So, we add ink.

sumi inked

Note how little ink there is, and this is enough to start. You can always add more ink later, but too much ink will come out all on it’s own…

As of right now, the sumitsubo is ready to go. A little more involved than the modern version, but still not a big operation.

Using the sumitsubo.

In use, these sumitsubo are very much the same as the modern version. You make a mark, run the line between the two marks, snap the line and you are done. Again, experience will tell you how much ink, tension and ‘snap’ to use to get the best results.

karuko loop

There is one point you should be aware of before starting, and that is to loop the line around the spike in the karuko. Just a small point, but important enough to make mention of. A single loop like this is fine, a double loop that may stay in place is arguably better. Double loops never stay put for me, so I just loop the line and stick the karuko in place before the line falls off.

running a line

And here we are, karuko in place and ready to strike our line. I will warn you to not place your mark up the board like I have done here, it makes things a little more difficult to line up later. Better to have the mark on the end of the board, and drive the karuko in right on your mark.

There is one major difference when using a sumitsubo like this when compared to the modern versions, and that is actually inking the line. The modern ink line usually has a way to apply some pressure to the wadding/sponge which then inks the line as it passes through. As a traditional style sumitsubo has an open reservoir, we need to apply pressure to the wadding directly.

finger inking

sumisashi inking

I’ll let you decide which way is best for you, but I go with using the sumisashi (translation; ink brush) to press down on the wadding, and it also keeps the sumisashi inked up and ready to use.

inked line

.And there we have it, a nice inked line.

Why not a few more for good measure?

finger ink

10 lines in about 1 minute, all parallel and without fuss. You can also see how little ink you get on your fingers after snapping 10 lines. The ink dries very quickly, and you won’t be leaving finger prints everywhere on your work, so even these dirty fingers are not going to cause any troubles.

In case you were wondering, the ink washes off easily with a little soap and water, for example…

inked hand clean hand

Same hand, with and without ink.

*****One final point, and a very important one.*****

DO NOT store a sumitsubo in a sealed container for any period of time!!!

A little alarmist? Maybe, but you might be thinking that you may wish to keep your ink line ready to use for the next time. One word, mould.

The modern, sealed versions have precautions against mould forming in their permanently wet ink reservoirs. These traditional style do not have any such guards, and placing them in a sealed container will promote mould growth, at least damaging the wadding and line, at worst condemning a beautiful wooden sumitsubo to the rubbish dump.

Leave them open and let the ink dry out. A little water the next time you use it will bring it back to life, good as new and mould free to boot.


Here’s the real caveat between the modern and traditional ink line. While the modern is cleaner and faster to use much of the time, the traditional style is only a little slower, doesn’t need to be messier and allows you to ink your brush instantly.

For outright speed, they are about the same, with the traditional style having a slight edge in some cases. For ease of use, again they are about the same, the modern style having the edge most of the time. For convenience, the modern style wins hands down as it’s ready to go within minutes, and can be made ready again in the future instantly. The traditional style needs more time to get ready for work but will work all day without a moments consideration. The traditional style can also use a much longer line, in those cases where the modern ones are found wanting.

I don’t think there is a clearly better way to go, and depending on how you work should decide which way works best for you. There isn’t anything faster for marking multiple lines out there.

Thanks for reading, and I hope the next time you see a sumitsubo, you are thinking “Hmm, maybe I should try one” instead of “How on earth does that work?”

Until next time,


2 comments to Sumitsubo (ink pot) set up and use.

  • Raney

    Really helpful information stu – and nicely written up. I’m just getting around to setting mine up, so this is really timely. Now if someone would just write up the best way to prep a new sumisashi, I’d be in heaven :)

  • Umm, take it and dunk it in the ink?

    You mean the brush part? I don’t use it myself, but the standard procedure is to make a few shallow cuts in the end to help propagate splits, whack it with a round faced hammer to break it up and add a little water to soften the fibres. I have seen older folks run a piece of copper wire around the end about 1/2″ up to stop the splits migrating up the brush, and I have seen old guys who leave it be, preferring to trim off the end when it becomes ugly and make up a new brush.

    The line marking end should be ready to go, save maybe back trimming the the pointy part. You might want to flatten out the thing if it’s become curved, but it shouldn’t affect things too much whether it’s bent or straight.

    Don’t worry, the next article will be sumisashi, a marking revelation. Really knocks your socks off the first time you use one and you won’t ‘lose’ any more pencils, because you won’t need them as much any more. ;)