At its simplest level, Tameshigiri is the traditional Japanese practice of testing swords by cutting soaked and tightly bound grass rolls called tatami, in fact it literally means 'test cut'.
This all evolved from early practices where instead of using the rolled grass mats everyone knows about, they used prisoners. Charming huh? :) There were a multitude of different cuts and these were actually explained in remarkably detailed books involving carefully drawn diagrams on how to restrain the prisoner so the cuts could be made. The results of the test cutting such as what cuts were used and how many times the cut was done, were inscribed onto the tang or nakago of the sword.
But eventually this was outlawed and the more humane alternative of using Tatami was used. It still is used today and so are a number of other things a lot more convenient to source and less expensive to buy. This is a serious consideration when you're first starting out as you're going to be making a lot of mistakes not to mention tatami isn't the easiest thing to cut, but then thats why it was used. So, the majority of the time, these other targets such as water filled bottles, rolled up newspapers and so on are used in leui of tatami and each of these present their own challenges.
Backyard Tameshigiri specifically involves cutting up targets, not in a dojo but wherever the practitioner wants to and feels they can safely do so. Also, originally the sword was the thing being tested, but nowadays it is the skill of the swordsman. It is their technique that is being tested instead. I also feel that backyard cutting is removed from normal martial arts in the same way that archery or fencing is.
Some cutters practice on their own with little external help but there are also groups both geographically close and therefore able to meet up in person, as well as internet groups who communicate primarily over social media such as youtube or facebook. It's up to you to take and give as much from these groups as you want to.
As a cutter you're going to have to learn things like how to grip and swing the sword, but you're also going to have to learn how to maintain it properly and most importantly, how to do all of this safely.
This article assumes that the sword you have is suitable for cutting. cheap wall hangers or stainless steel blades do not qualify. You need a decent high carbon steel blade that was made specifically for the purpose of cutting. If in doubt, do not use it.
Before doing any cutting, you need to do a quick check over your sword. You need to check to see that the wrap is still nice and tight, the mekugi pin is seated snugly and that there are no chips or rusting on your blade.
Keep a good grip on your sword. When sheathed, I find it best to keep your hand on the saya and your thumb on the tsuba just in case. Better to be safe than bleeding.
Make sure your cutting area is free of people, pets and objects and close the door to the area. You might have friends or other participants around and if you do, make sure they know to stay well back whilst you're cutting. It's very easy to not notice someone when your attention is focused on the target. Remember to stand back yourself when others are cutting.
This one goes without saying but I'll say it anyway. Never cut if you've had a drink, feel unwell or are unduly tired. If you're not 100% then you'll make mistakes.
Finally, whatever you are using for a cutting post to place your targets on, should be made of wood or something just as soft. It is dangerous to risk smashing your blade against something hard.
None of this is said to be a killjoy or a pain in the ass, making sure youve done all this will save you a trip to the hospital.
There are a number of targets that you can use and there is plenty of information and videos out there so I wont go into detail. Bottles can be cut both full of water and empty although empty bottles are far more challenging.
Soft drinks bottles both 500ml and larger. The smaller ones are best for stacking on top of each other for double or even triple cuts. Mineral or spring water bottles tend to use thinner plastic and so they're much easier to cut. The fizzy drink bottles are thicker and harder to cut.
You can use plastic milk cartons which are much easier to cut and to get multiple cuts on the same bottle with. Not only that, because they slice so easily they present the added quirk of showing you your cutting line through the bottle. Useful for showing you if youre scooping your cuts or letting the blade fall or rise mid swing.
For a cheap tatami like substitute you can use rolled up newspaper which is soaked and then allowed to dry off a bit. Don't use too many sheets, its deceptively tough. For this you'll likely need a peg to stick the roll into like a traditional tatami stand but free standing cuts are possible with practice.
There are also things like Pool noodles or hanging paper sheets. Some people even cut fruit but I'd suggest cleaning your blade straight away afterwards if you do as the acidic nature of most fruit will damage the blade left for any length of time.
Maintenance after cutting
Being made of carbon steel means that a little extra care needs to be taken after you've done any cutting or practice in order to prevent rust. There are far more comprehensive guides out there but the basics are here.
You should have a sword care kit which will have a powder ball, some form of sword oil and some cloth.
Firstly wipe off the blade with a cloth and apply powder by tapping the powder ball against each side of the blade a few times. Use a different cloth to wipe the powder along the blade, cleaning and removing any excess moisture.
You'll need to oil the blade again. simply put a couple of drops of oil onto each side of the blade and use another cloth to spread the oil over the entirety of the blade.
Once this is done you can put the sword back into it's saya trying not to touch the blade with your hands and put it somewhere safe. Remember that this needs to be done every time you practice regardless of whether or not you've cut anything.
Someone once said to me that the essence of backyard tameshigiri isn't in the cutting of the target but in the control of it. Being able to cut a target and have it predictably fall one way or another, or being able to remove part of it to line up your next cut is where you really start to demonstrate skill. All of this of course takes discipline and practice, repitition and passion.
I hope that helps somewhat to at least give you an idea of what backyard cutting is about, but of course nothing will show you quite like just getting up and having a go, just remember to cut safely.