Tombak Opinions Wanted

[Nagawarrior]

I recently acquired this nice Tombak from one of our esteemed fellow formites. I'm trying to learn as much about it as possible. I can really use your help.
I understand it is hard to give an evaluation using photographs.
First of all I realize it is "out of stain" and it exhibits characteristics that make it difficult to identify as a Javanese Tombak. (Thank you to Alan Maisey for that information). If anyone might have an opinion I would love to hear it.
Another question I need an answer to is; where can one find laboratory grade white arsenic (arsenic tri-oxide) ? Does anyone know the difference between a Tahitian lime and a regular lime. Both these are needed for proper staining according to Alan's detailed instructions.

[Battara]

On the ferrule, it looks like a postmark plane for airmail. Could the brass have come from some postal box?

[doecon]

Please dont play with arsenic yourself, just leave it to proffessionals. I'm sure there is some small businesses in your area that can do it for you. I clean a lot of blades, but the staining itself I leave to others. see link below for some of the better reasons

http://www.jtbaker.com/msds/englishhtml/a7512.htm

[Rick]

I'm betting that California is a tad shy on keris staining shops Doecon .
The Tombak looks pretty good as it is anyway IMO.

If it were mine I'd let sleeping dogs lie .

Does anyone feel like offering an opinion on the specific origin of this style Tombak ?

[Nagawarrior]

Originally Posted by doecon

Please dont play with arsenic yourself, just leave it to proffessionals. I'm sure there is some small businesses in your area that can do it for you. I clean a lot of blades, but the staining itself I leave to others. see link below for some of the better reasons

http://www.jtbaker.com/msds/englishhtml/a7512.htm

I thank you for the warning Doecon. You are right, arsenic is highly poisenous. Probably the reason I can't find it any where. My wife already expressed concern. She thinks I have nefarious motives to get life insurance money to collect more swords

I think it looks pretty good as well Rick. I used the old Radio Shack etchant. I've tried all kinds of acids to try to get a good etch/pamor but none look like the arscenic method. I've been told this is the only way to really get the pamor stain right. I believe I could use the ascenic method safely and get good results. I haven't seen any Kriss stain shops in any of the malls in Southern California, your right about that. Sending it off to Alan is a bit cost prohibitive and the chance of the Tombak getting lost isn't worth it either.
Stephen*

[nechesh]

Originally Posted by doecon

Please dont play with arsenic yourself, just leave it to proffessionals. I'm sure there is some small businesses in your area that can do it for you. I clean a lot of blades, but the staining itself I leave to others. see link below for some of the better reasons

http://www.jtbaker.com/msds/englishhtml/a7512.htm

I am afraid Rick has a point Doecon. Not many mom & pop shops doing traditional keris staining in my neck of the woods either. Also, some collectors like to take a hands-on DIY approach to their collections. I've been working with this process for a couple of years now. Common sense is, of course, a necessity in the handling of a substance like arsenic and your link is a valuable resource and much appreciated.
I also agree with Rick that this tombak isn't in too bad a shape. I would just keep it oiled for now.

[doecon]

Just curious;

aren't there services for staining iron at all? Some contracters who do protectionwork for your fence or interior? Probably they are using similar substances. Maybe iron staining is used in some other proffessions as well? Who knows if they can stain your fence, they might be able to do your Keris as well
(I havn't tried since I have found a pop & mom place next door).

For the sake of keeping your item in a good condition I would recommend to have it stained. (Keris) Oil can however already have a nice effect, since it normally brings a bit of extra contrast. But he, its your spear, please do with it what you want.

Regarding its origin I hardly dare to comment since Alan has given an opinion already From the pictures included my uneducated guess it is central java made around 18th century. In case the ferule is not seperately forged, place and time might differ. (madura)

The little holes might have been drilled in later times for decorational purposes, I dont think they are part of the original design.

[Rick]

There's a staining shop in Florida ?!
Please tell me where .

[nechesh]

Doecon, i somehow doubt that if one were to find a place that stains iron for, as you suggested, fences, that they would be using arsenic and lime juice to do it. And as you probably are aware, while there are other substances that will darken iron while leaving nickelous material bright, none of them will give the proper color to the iron as is expected in a keris. Whatever protective treatment that companies use on iron fences would not be the same kind of thing and i don't believe warangan is applied to a keris to protect the iron anyway. Even if i were to find a company that for some reason did treat other metal objects like fences with arsenic and lime, i don't think i would be too keen on having them stain any of my keris. This is a process which involves a bit of subtelty, practice and skill so i'm not sure such workers would have the necessary understanding to get the staining right. Anyway, there is a certain satisfaction to be had in doing the job yourself. Still, if i were to find someone locally (or even in the States) who did this work correctly i might be inclined to use their services.
I am glad to hear that you have found a local place to do this work. Like Rick, i would also be interested in knowing who they are since i was unaware that there were any professional keris stainers in the United States. Do they use traditional methods?
Your statement about Alan giving his opinion on this tombak confuses me since i do not see that he has posted here. Can you explain this remark?

[doecon]

Sorry for the misunderstanding, the guy next door isn't in the US. I'm located in the one and only country that has fully dressed playmates in their local playboy. Indonesia. (the other half of doecon is in florida

Since I fully symphatize with you lacking a stainingservice, I was trying to opt. some alternatives. Another hint, I did read some time ago about a guy in the US doing this service for others..Unfortunatly I have no record. The only thing I remembered was that he was doing restorations as well. Try google him, who knows.

Another Idea, bit farfechted though, try to organize a little yearly keris-cleaning party. I'm sure there is enough support for that. (If needed I'll put my cleaning guy in a plane.

Shipping your item here is simply a bit risky and expensive, I would love to help out but you have to pay for your own return postage. (50US for a keris)

Regarding the tombak, IP mentioned that Alan had reason to believe some features might be indicating other origin then Java. Wasn't me, but I would not dare to argue

Alan, come on in ..the floor is yours...

[Rick]

Originally Posted by doecon

Sorry for the misunderstanding, the guy next door isn't in the US. I'm located in the one and only country that has fully dressed playmates in their local playboy. Indonesia. (the other half of doecon is in florida

Ahh , two branches to the doecon family ; I wondered why the discrepancy .

In the States any one caught using arsenic on any exterior structure would probably be drawn and quartered by either the EPA or OSHA . Even copper sheet for valleys or entire roofs has been reformulated .

[nechesh]

Well, that explains alot. I was assuming your location based on your ebay address in Florida.
Believe me, i would gladly trade naked playmates for a corner mranggi any old day.
Yes, as you point out, there are a number of reasons why a U.S. collector might not want to ship a keris overseas for staining. For me the least of it would be the cost, though that is a factor. The staining service itself is cheap, but after tacking on round-trip postages and handling it's a pretty pricey process. But personally i am more concerned about getting my keris back in one piece if at all. There are all kinds of circumstances undr which it could be damaged or lost. Then there is the worry if one has an undiocumented ivory hilt, for instance. It may not make it back through U.S. customs.
The yearly cleaning party idea sounds interesting, but i think it might actually have a greater environmental impact if many keris are being cleaned in one place at the same time. As i said, i personal enjoy staining my own keris. It's not for everyone, i'm sure, but working with keris on this level has only increased my appreciation and knowledge of these blades. For those who are considering it i highly recommend that you start out on some low quality blades that you aren't too worried about. I was fortunate to get my hands on some that i really could only make better, since they were in pretty bad shape. Practice makes perfect..... or at least makes better.

[A. G. Maisey]

Thank you Mr. Doecon, for your invitation to participate.

What I actually said was this:-

"---I`m sorry, but I really am not positive at what I am looking at here.

Yes, its a tombak, but it is out of stain, and there are some characteristics that make it difficult for me to identify as a Javanese tombak. It may be Javanese, or it may not be. It appears to be in overall good condition, ----
There`s just not a lot I can tell you about this *****. Commentary on Javanese wesi aji starts with an attempt at classification, and because this is out of stain and has some non-typical ( for Javanese) characteristics, there is no way I could make a sensible classification. Sorry.---"

I do not know what is , and if I do not know, I`m not prepared to guess.

If I had it in my hand the story could be different, but giving positive ID`s on the basis of a photo is something that I am often just not good enough to do.

[nechesh]

Well Alan, as you know, i am merely a student of the keris, but i know even less about tombak. Could you tell us what characteristics about this tombak are non-typical to Javanese origin. It might help Doecon's understanding of why you hesitate to classify this one and it would probably help my understanding of tombaks as well.
Personally i think anyone would be somewhat foolish to claim they can make a positive ID of keris and tombaks based on a few photos viewed on the internet. Photos, even apparently good ones, can easily mislead as to tone, hue and color and give no indication of weight or feel.

[Nagawarrior]

Thank you for your input here Alan. I didn't want to print your full reply to me without your permission so I just thanked you when I started this thread. I hope I haven't committed a faux pas.
I still would like to know where I can obtain some of the arsenic trioxide for staining here in California. Can any one help with that? I find great pleasure in hands on care of items in my collection and really want to try to stain myself. I probably wouldn't start with this Tombak. Rather as suggested, start with a low grade Keris I have so I may learn. I have used the method suggested by Alan in the past, but had to resort to Radio Shack etchant for the acid. This does not produce the pleasing look I want. It works well on other swords I might say.
Thanks to all here for your replies. They are much appreciated

[doecon]

Just a few notes regarding some above;

No positive ID given, just guesswork here from my site. Its obvious that an ID would require more info/better pics. As mentioned I have no idea how the ferule is forged, no pics no info.

Neshech;
I noticed you mentioned that "warangan" isn't for protection; actually both the "acid" bath and the final oil ritual are in some way. Acid bathing stops or limits the oxidation. just for the record

Naga;
I was under the impression that your Radio Shack was used to replace the arsenic substance (I had no idea you ment the acid). For the acid itself you can use lime. (locally they use the small green ones). This acid is used in the first step, as in cleaning your tombak. Once fully done (might take days) you will have a nice "white" tombak..then you start "staining" . Just google "warangan", you find some pretty good descriptions of the process in the first hits.

I'll try to dig up some uncleaned (old) blades as "practising material" and will post them for you in the swap forum if needed. But please keep in mind that some of us (including myself) have some kind of respect for these sharp old things, so please do handle your blades likewise.

[Nagawarrior]

Originally Posted by doecon

Naga;
I was under the impression that your Radio Shack was used to replace the arsenic substance (I had no idea you ment the acid). For the acid itself you can use lime. (locally they use the small green ones). This acid is used in the first step, as in cleaning your tombak. Once fully done (might take days) you will have a nice "white" tombak..then you start "staining" . Just google "warangan", you find some pretty good descriptions of the process in the first hits.

I'll try to dig up some uncleaned (old) blades as "practising material" and will post them for you in the swap forum if needed. But please keep in mind that some of us (including myself) have some kind of respect for these sharp old things, so please do handle your blades likewise.

Yes doecon, the Radio Shack etchant is used in place of the arsenic mixed with lime juice. I use pinapple juice and soak the blade and rub with a tooth brush to clean. Finally I use the etchant to bring out the pamor. I have a complete instructions, I believe they were posted on this forum in the past. I just substitue the arsenic with etchant. It really doesn't work very well on Keris. I've had great results on other types of swords.

I appreciate the reminder of the great reverence that one should have for these important cultural objects. I'm trying my best to show respect by wanting to properly care for them and learn as much as possible from this forum. Sometimes I feel I'm a bit clumsy in this process. I hope no one feels I have acted with any disrespect. If so I certainly apologize.

[nechesh]

Doecon, my understanding is that what is known as warangan is not the acid bath, but the mixture of arsenic and lime that is used for staining the keris after thye acid bath. Certainly if one is removing rust in the acid bath step they are helping to "protect" their keris from being eaten away by rust by stopping present oxidation. The warangan blackens the iron, therefore raising the pamor. It's main purpose seems to be aesthetic to me though it may help reduce rust in the future. Keris oil, on the other hand will definitely help protect a keris from future oxidation. It does, of course, have ritual purpose as well.
The Radio Shack etchant which Naga speaks of is indeed an acid etchant, but it doesn't "whiten" the blade like a traditional acid bath will, but darkens the iron like warangan does. As Naga points out, it works well with some swords, but the color it produces is not the same as warangan and therefore not correct for keris. If Naga is familar with the methods Mr. Maisey has suggested then he probably doesn't need to do a google search (though i guess you can't have too much information). I have been staining keris with this method for 2 yrs. now and i am more successful every time. Though i am glad that i started out on some low grade damaged blades. Believe me, even these i worked with much care and respect and left them in much better shape than i found them in. Your implication that any of us would treat these blades with disrespect, or that you somehow know better about such things is assuming to say the least.
BTW, in regards to positive ID, my statement was a response to Alan's remark that he wasn't "good enough" to make a positive ID with the given information. I suppose Alan found it necessary to explain his caution after your somewhat sarcastic remark that you "hardly dare to comment since Alan has given an opinion already" . I in no way implied that YOU had made such an ID nor was i trying to say that YOU were somehow being foolish. Not sure why you are being defensive on this issue but i would appreciate it if you would not project on my statements.

[A. G. Maisey]

No Stephen, no problem with the name.

David, I didn`t say that there were non-typical characteristics, I said there were characteristics that made it difficult for me to identify as Javanese.

The overall look and proportion don`t click into a tangguh slot, the ada-ada is very thickly ridged, the material looks a bit porous but this might just be excessive use of acid in cleaning, the metuk---this will be found to be mechanically attached, not forged as one with the blade--- the metuk could possibly fit a couple of classifications, but it seems to combine characteristics from at least two different classifications, possibly three. It might be Javanese, but without it in my hand, I`m not prepared to say. Look, this is not a top level, court quality tombak:- its a nice old fairly middle of the road example. Tangguh was never intended to apply to every piece of wesi aji under heaven, and the further away you get from court standards, the more difficult it gets to fit any wesi aji into a tangguh slot. Tombak are much, much more difficult to classify than keris at any time, and when you get a few pics of something that might or might not be Javanese, its just too hard to be positive about anything. In the hand it may be possible to look at different angles, or examine the texture under a loupe, or gauge the weight, or feel the texture, but from photos I`m afraid its beyond me. Now, if I were to take a punt and say---yeah, OK , probably Javanese---the next question is---oh, its Javanese is it? How old? What tangguh?--- my answer---I don`t know---well how can you say its Javanese?

Actually, my gut feeling is that this tombak could be Balinese.
But don`t hold me to it---that is just a gut feeling, based on a photograph.

As far as staining goes, why not start with this tombak?
I personally think it would be a good thing to start with.
At least its got good clear pamor that you can be fairly confident will show up OK after staining. A lot of old blades, especially old junky ones just show grey and grey with low definition, and a beginner doesn`t know if he`s on the right track or not.
Give it a good scrub up with hot water and dishwash detergent, a light bath in pineapple juice,rinse off,dry, and go right to it, as long as you can get the arsenic, and that might be the hardest part.
One thing is certain:- you cannot do it any harm. If it turns out too dark, you just clean it off with bonami or some other powder sink cleaner--ajax maybe---and try again. In Jawa we use abu gosok---an ash used to polish pans--- and coconut husk, but ajax and steel wool works just as well. I`ve been playing around with cleaning and staining for about 45 years now, I`ve been taught several different methods and have developed a couple of my own. There is no magical secret attached to blade staining, its just patience and experience, and if you get it wrong, clean it off and try again.You definitely cannot do any damage to the blade if you tackle the job correctly.

[doecon]

Thanks Neshech for your explanation, I wasn't in defense, maybe just a bit short in my answer before. Just wanted to repeat that I made a guess only, for the record (IMO the only thing we can do, even upon studying the item from nearby, although the guess might become more better

I honestly respect Alans opinion and I had no intend to be sarcastic, I pretty much meant what it said and the quote should include the "smiley". But for reasons of clarification; If somebody posts an item for ID but mentions that a forum member has already established some indication, then this member (Alan) should have a say first.

Regarding the cleaning itself, I think you should be a bit careful with the steelwool on your blades. Some might prefer a careful start to remove dirt and rust, by using softer material. A piece of wood (softer then steel) is a good and safe scrubber. But as I mentioned before, its your blade, so have fun.

In case you still need some practice material, I brought 3 very good “practice” blades. I will post them in the swap section tomorrow.

[nechesh]

In regards to steel wool there are many grades of courseness. Personally i would only use the finest grade which is #0000. There is very little chance of scratching or otherwise damaging the surface of a blade with this stuff even when working with it quite vigorously. In essence it is a "safe scrubber".

[doecon]

Neshech, I never tried, but you sound convincing enough. Just hope I can find that fine grade around here.

Since we are going slightly off topic I want to do a final effort for IP to give him some (very uneducated) clues about his item.

My main focus is the size of the bottom of the ferule for a first indication. It’s (again in my humble opinion) mostly seen in heavier and larger spears, which makes sense if you imagine the force used with these things (Some were over 2.5 meters long). These spears are called landeyan (I believe) and indeed used in Java and Madura.

(Always wondered if the name could come from the dutch, langejan=Long John; no prove though but the period seems to match).

The dapur is in my opinion common for java. The higher section in the center has the function of removing the spear more quickly after contact with its target and it will create more damage. (The broader base helps to increase the “stopping” power). There is a kind of dapur originally containing holes, but I forget the name ) Holes look a bit like made in later stage. If they were not then Java comes to mind again. As mentioned the are probably for decoration purposes, since these spears were used in (keratin) parades as well. (they still do have those parades)

Pamor doesn’t have the "madura" feel, the small lines on the side of the blade are more seen in java pieces ...it doesn’t really match from what I see from Madura.

Dating is a rough quess, but I placed it somewhere between the arrival of the Dutch and from the looks of the spear not younger then 200 yrs. Markings of numerous cleanings would have had its marks not only in the ada-ada area but on the side as well. I have no specific comment on quality, since its obvious not created for royal ceremonies. However from what I see it looks like it has been actually used (which is not really that surprising). 2 smaller cuts on the side and traces of scars in the center, so I would argue that its not well made. From the “wear” around the border, the well shaped “ferule” I would call it good quality.

There is some older drawings from actual spearfights (maybe on the web as well), could maybe give you some clues as well.

Regarding the later added hilt, I agree that its probably some mark. Maybe you can find details with the KLM (Royal Dutch Airlines), since they were the first and for long time single airmail provider in Indonesia.

General disclaimer : I’m just an amateur in this area, but I hope it has been of some help.

[A. G. Maisey]

Use of steel wool on wesi aji:-

As David remarks, there are a number of grades of steel wool.

One obviously selects the correct grade for the job at hand.
0000 steel wool is used for polishing fine cabinet work prior to applying the finish, and it will definitely not damage iron or steel.

My recommendation for use of steel wool was not associated with the initial preparation of a blade prior to staining.
When somebody first attempts blade staining, a common error is to make the blade too dark. I was recommending the use of steel wool and a powder sink cleaner to remove the stain that is too dark before attempting the job again.Where the stain is only a little bit too dark, or if one wishes to emphasise an area of white pamor material, rubbing down with the inside of the lime skin, and frequent rinsing will often give the desired result.

However, having said that, as a final preparation step prior to beginning to stain, a scrub with steel wool and powder cleaner is also useful. The blade should be a good white prior to commencing to stain.

A common defect with the work of people who stain blades in Jawa is that patches or spots of yellow or brown will be seen under the black. This is usually caused by failure to adequately prepare the blade by bringing it back to a good white, before commencing to stain.

There are a number of levels of quality in blade staining:- a commercial stainer, is capable of handling a large number of blades in a single day by using a method involving the soaking of the blade. This type of staining is a very low cost process, however, there is a failure rate of somewhere around 50% , if we measure against perfection of result.

Other common methods can use more time than the soak method, and are consequently more expensive, but have a higher rate of success. The very best method that is used on high quality wesi aji , and is probably thoroughly understood by only a very limited number of people, can use several days to stain a single blade.
The times I am talking about here are for staining only, beginning with a perfectly clean blade.

To the best of my knowledge steel wool is not available in Jawa.
I have taken steel wool to Jawa, and it was extremely troublesome to prevent from rusting during the wet season.
However, as I have previously remarked, in Jawa abu gosok and coconut husk is used for cleaning or polishing a blade during the staining process.Steel wool is unnecessary.
On an old blade with rough grain, steel wool is not really such a wonderful thing to use, as the threads of the steel wool get caught in the raised grain of the blade. For blades like this a nail brush and powder cleaner, and/or a Scotch Brite pad is probably more practical.

I hear a lot about the great care that must be taken with blades in cleaning and staining, but in truth it is almost impossible to damage any wesi aji if plain common sense is used. This remark does not apply to blades with kinatah work.
The greatest damage can be done during cleaning by the use of acids that are too harsh.
A traditional cleaning acid is coconut water, however, this is seldom if ever used by commercial blade stainers.
They use citric acid, and in fact any type of acid, including sulphuric and hydrochloric, to get a blade clean.These acids are really much, much too aggressive for blade cleaning, but they have the virtue of being fast.

I believe that most of the blades that we see these days with very open grain are probably like this as a result of cleaning with these aggressive acids.

Outside of Jawa, I have only ever used canned pineapple juice for cleaning a blade. On a spot of stubborn rust I will sometimes use a drop or two of hydrochloric, but after the spot is clean I kill the hydrochloric with bicarb of soda, and I always finish the blade in pineapple juice.

The shaped baluster that is found at the base of a tombak blade is called a "metuk".

The word "landheyan" (landeyan) is ngoko for a tombak shaft, and can also be used for a keris handle. It has the same meaning as "jejeran" does in krama and krama inggil. The word "landeyan" is also found in Old Javanese, and in this language has a similar meaning.

[John]

Great stuff Alan and so good to see you on board and unreservingly sharing invaluable information directly.

[Tim Simmons]

Fascinating, can you etch with the more gentle fruit acids? I might be tempted to experiment on some tourist junk I have. Then who knows what next

I might even risk this as I got it very cheaply, if you could see it in the raw, you would see that the blade is full of pattern lines or what you call, pamor?

[A. G. Maisey]

Let me differentiate between "etch", and "stain".

If we etch something, we bring up the topographic relief that is revealed when the acid eats away the softer metal.

If we stain, we apply a substance that will reveal the colours of the differing materials in a blade.

Before attempting to stain a blade we must clean it of rust and dirt. A gentle fruit acid such as pineapple juice is a very effective cleaner, and will also very lightly etch.

When we look at an old blade we can sometimes see lines in the blade that look as if they may be pamor, however, with many old blades we are not seeing pamor, we are simply seeing the weld joints caused by the folding process used in cleaning the material before it was forged into a blade. You can sometimes see these weld joints in old European pieces too.

Sometimes with an older piece of wesi aji, a soak in pineapple juice will not only clean the blade, but will also reactivate the latent arsenic from previous applications, and you can get a half-way acceptable blade finish by the use of the pineapple juice alone. You may find that this could be the case with the tombak you have shown.

[Henk]

Originally Posted by Tim Simmons

Fascinating, can you etch with the more gentle fruit acids? I might be tempted to experiment on some tourist junk I have. Then who knows what next

I might even risk this as I got it very cheaply, if you could see it in the raw, you would see that the blade is full of pattern lines or what you call, pamor?

Tim,

Looks to me as a nice tombak and certainly not a tourist piece. Does it have a scabbard?

Of course you can clean it with more gentle fruit acids. Pineapple juice and coconut milk are frequently used to clean the blade. The pattern lines you see are the lines from the forging of the metal. The pamor is the contrast of the nickle and the iron made visible by the warangan. It depends how the nickle is twisted with the iron and how many times, but you would be surprised of the pamor patern coming up after treatment with the warangan. That the blade is full of pattern lines indicates that your tombak has pamor.

[Tim Simmons]

This does have a scabbard with a thin slice of turtle on the outside. I have shown it in the past.

I have the tombak set up like this, in the opening of a pot. It has been like this for about 4 hours, I think something is happening I can smell it. Every now and again I move the blade in and out of the lemon to keep the juice wet. How long should I keep this up, days?

[doecon]

Mhwaauhaha, great experimental setup. I think you should leave it a couple of days I bet you will see some nice shinny "white" blade...

[nechesh]

This seems like a somewhat awkward set up to me Tim. Is there some reason why you didn't just remove the hilt and immerse the blade totally in something like pineapple juice. I wouldn't think the citrus is all that helpful to the hilt anyway. With total immersion you wouldn't have to worry about moving the blade in and out all the time. The cleaning would be more even. I'm also not sure you will get a "white" blade this way. If your photos are any indication it looks like the citrus has re-activated some of the old warangan. At least it appears that the iron is darkening in some areas, especially around the edges and lightening where there may be pamor. But perhaps that is just a photographic illusion. If you plan on re-staining this one you might need to employ a bit of scrubbing to get this tombak "white". Of course, if you don't plan on restaining, the lemon treatment might just bring out the pamor to your satisfaction. Either way, be sure to neutralize the citrus with something like a slurry of baking soda to stop the action of the etch.