Arches Platine

[Manuel G Teixeira]

I checked the last 20x16 batch i bought, that was 5207 too. From my undestanding CoT 320 is made by Arches, Bergger than market it.

I find Cot 320 very similar to Platine, (the later being less off white) so with the bad batches of Platine flying around it would not surprise me if some of the latest Cot 320 batches might be effected.

David,

I've a strong felling that you're absolutely right. I suspected that they don't produce any products at all, they simply rebrand them. A.Platine and COT320 are very similar indeed and the eventual differences you can find must be caused by different batches origins.

Here in Europe, is easier to find COT320 than Arches Platine, at least in smaller sizes.
Were do buy yours? John Purcell I suppose ? They indeed have a great selection of papers. I've been there last year, but the cost of sending large sizes of Platine to Portugal was very high. Nevertheless, I've ordered Gampi and Kozo. The tests I've made with the Platine samples from them were not brilliant and were inferior to those I'm getting from the good batches of COT.

 

[cabestan]

I've a strong felling that you're absolutely right. I suspected that they don't produce any products at all, they simply rebrand them. A.Platine and COT320 are very similar indeed and the eventual differences you can find must be caused by different batches origins.

In 2008, Dana Sullivan (from Bostick & Sullivan) (there was a url link here which no longer exists):

Arches Platine: Why we didn't carry this paper until this point, I'll never know. Wonderful cool/natural colored paper that is the half brother of Bergger COT-320, since it is made on the same machine, in the same factory, to very similar specs. I find that the surface resists the coating solution a little more than the COT-320, which gives me more time to spread it evenly.

The main difference seems to be the absence of a watermark on the COT-320. Maybe also a slight difference of sizing.

 

[Davec101]

In 2008, Dana Sullivan (from Bostick & Sullivan) (there was a url link here which no longer exists):


The main difference seems to be the absence of a watermark on the COT-320. Maybe also a slight difference of sizing.

Thanks for this info, it makes sense to me and accounts for the premium price COT-320 is over Platine. I got a good deal on a large order of COT 320 but would not buy it again if Arches finally gets the new batch of Platine out as i did get get a higher dmax with the previous batches of Platine.

 

[Manuel G Teixeira]

In 2008, Dana Sullivan (from Bostick & Sullivan) (there was a url link here which no longer exists):



The main difference seems to be the absence of a watermark on the COT-320. Maybe also a slight difference of sizing.

Last year, when I was asked to test their new batch Beta samples, I suppose from what would be called #5214/1, they told me the following: "Quality is the same as usual but some improvement has been made concerning the amount of gelatine /sqm".

With this batch, as I told before, I suppose, it was quite impossible, (at least with my printing procedures) to get acceptable results with the coating rod. Nevertheless, even with the magic brush, I could not get a brilliant Dmax (no more than 1.45.

In a few days I'll test their very last batch available (#5214/2), and sincerely hope to get better results. This paper when is properly tuned can give sumptuous results with Pt/Pd.

If you compare the COT-320 (#5213) with the Arches Platine(#S104 617) I ordered from John Purcell, the last one seems slightly creamier and smoother in both sides.
Testing those two papers with a PH Pen, they both give acidic results(as they should) of similar values. Please be aware that this test gives only a rough idea of PH values.

 

[cabestan]

Manuel,

I bought some COT-320 at Bostick-Sullivan last year (I haven't any batch number) and I had similar results to yours. Poor Dmax with the rod as with the Richeson brush. Good Dmax but very grainy results with foam brush.

I managed to get better results with a prewash in acidified water (with citric acid, not for inexistent calcium carbonate buffer, but by precaution because my tap water has a ph of 7.8).

Pre-wash et foam brush have the same effect : attacking the surface sizing. So, I think it was just a sizing problem.

For the differences between the Arches and the COT-320, I currently have in stock : Arches Platine from Bostick-Sullivan, Arches Platine from a local shop (De Serres) and COT-320 from Bostick-Sullivan.

COT-320 and Platine from BS are identical (same color, same grain).

The Arches Platine from BS is smoother and slightly less yellow than the Platine coming from my local store. So all seems to be a question of batches.

I look forward the next version of Arches Platine. Any news?

 

[Manuel G Teixeira]

Manuel,



I look forward the next version of Arches Platine. Any news?

I suppose that some sheets of the COT320 last available batch (#5214/2), probably will arrive by the end of next week, so only then I'll be able to proceed with the tests, of course. I'll be delighted to share my first impressions with you and all the other members of this forum.

 

[Davec101]

Have just today had some clearing problems with cot 320. What are you guys clearing this paper with? At the moment my clearing method has been.

5 mins citric acid
5 mins EDTA-Disodium
15 mins Hypo Clearing Agent
15 mins EDTA Tetra

It has been working fine for the last couple of weeks however the last few prints have not cleared properly. I have attached a cut sample of what is left after the clearing cycle above. This area was covered with rubylith tape and should obviously be clear. Am going to try a new developer and ferric oxalate to see if that is the problem tommorow. Any other ideas?

 

[Manuel G Teixeira]

Have just today had some clearing problems with cot 320. What are you guys clearing this paper with? At the moment my clearing method has been.

5 mins citric acid
5 mins EDTA-Disodium
15 mins Hypo Clearing Agent
15 mins EDTA Tetra

It has been working fine for the last couple of weeks however the last few prints have not cleared properly. I have attached a cut sample of what is left after the clearing cycle above. This area was covered with rubylith tape and should obviously be clear. Am going to try a new developer and ferric oxalate to see if that is the problem tommorow. Any other ideas?

David,
I'm only using HCA with great success.
Periodically I make a clearing test, similar to yours, blocking to UV light a small area of the emulsion.
Curiously I never had any clearing problems with this or other papers.

Do you add Oxalic Acid to the Ferric Oxalate sensitizer ? If not, one of the possible answers can be there.

 

[Davec101]

David,
I'm only using HCA with great success.
Periodically I make a clearing test, similar to yours, blocking to UV light a small area of the emulsion.
Curiously I never had any clearing problems with this or other papers.

Do you add Oxalic Acid to the Ferric Oxalate sensitizer ? If not, one of the possible answers can be there.

Hi Manuel

I get the powder bottles of Ferric oxalate from B&S which i am sure have a small amount of oxalic acid in. How much OA are you adding to a 25ml bottle of FO?

I will try 3 baths of HCA tommorow to see if that helps. The water that comes out of my taps is quite alkaline so it seems to need more clearing other people. The majority of the prints i make have rubylith around the negative to create a clean border, so there is no getting away with uncleared prints!

 

[pschwart]

I think 40 minutes of clearing is significant overkill. I do 5 minutes in citric acid, 5 minutes in EDTA+sodium sulfite, and 5 minutes in hypo clearing agent (or Permawash). I do make sure that the baths are fresh; prints clear completely.

Have just today had some clearing problems with cot 320. What are you guys clearing this paper with? At the moment my clearing method has been.

5 mins citric acid
5 mins EDTA-Disodium
15 mins Hypo Clearing Agent
15 mins EDTA Tetra

It has been working fine for the last couple of weeks however the last few prints have not cleared properly. I have attached a cut sample of what is left after the clearing cycle above. This area was covered with rubylith tape and should obviously be clear. Am going to try a new developer and ferric oxalate to see if that is the problem tommorow. Any other ideas?

 

[Manuel G Teixeira]

Hi Manuel

I get the powder bottles of Ferric oxalate from B&S which i am sure have a small amount of oxalic acid in. How much OA are you adding to a 25ml bottle of FO?

I will try 3 baths of HCA tommorow to see if that helps. The water that comes out of my taps is quite alkaline so it seems to need more clearing other people. The majority of the prints i make have rubylith around the negative to create a clean border, so there is no getting away with uncleared prints!

Hi again David,

Im order the metals and FO in powder from B&S and I always add OA to the sensitizer as follows:
-100ml H20
-27 grs FO
-2grs OA

I don't suppose B&S add OA to the ready made solution of sensitizer.
Other way of helping the ferric oxalate go into solution is to add EDTA Tetrasodium.


This, and to give full development will for sure help to solve your clearing problem.

What developer are you using ? Plain PO solution ? Do you check the developer PH regularly?

 

[Davec101]

Hi again David,

Im order the metals and FO in powder from B&S and I always add OA to the sensitizer as follows:
-100ml H20
-27 grs FO
-2grs OA

I don't suppose B&S add OA to the ready made solution of sensitizer.
Other way of helping the ferric oxalate go into solution is to add EDTA Tetrasodium.


This, and to give full development will for sure help to solve your clearing problem.

What developer are you using ? Plain PO solution ? Do you check the developer PH regularly?

Yeah am using plain PO. I made a new batch only 4 days ago, i have ran out of PH strips but it should not have gone alkaline in such a short space of time. I spoke to B&S and they said they dont add oxalic acid to their FO any more. So maybe will give that a try tommorow with some fresh FO. For 25ml i guess one adds just a pinch, like half a gram?

 

[Davec101]

Okay it was fog, i have been switching around digtal negative systems and the masked border was not providing enough uv blocking so i doubled up with rubylith and that solved it. Phew...

 

[DennyS]

I'm a bit confused in reading the last posts, it seems as though you expect potassium oxalate to be acidic, but I've just mixed up a fresh batch of plain po and I'm getting a pH of about 7.2. I've never seen any recipes that call for acidifiying po, or adding oxalic acid to po. I do remember an old thread on replenishment that indicated that the developer should be kept acidic at about pH 6. Are there any references to this in any literature or is this a recent trend?

Do you replenish? Replace? How often? (I've seen many references that indicate that po lasts "forever", it doesn't seem to last very long in my experience with pt/pd.)

Sorry for all the questions, just trying to do the right thing...

Thanks,
Denny

 

[Manuel G Teixeira]

I'm a bit confused in reading the last posts, it seems as though you expect potassium oxalate to be acidic, but I've just mixed up a fresh batch of plain po and I'm getting a pH of about 7.2. I've never seen any recipes that call for acidifiying po, or adding oxalic acid to po. I do remember an old thread on replenishment that indicated that the developer should be kept acidic at about pH 6. Are there any references to this in any literature or is this a recent trend?

Do you replenish? Replace? How often? (I've seen many references that indicate that po lasts "forever", it doesn't seem to last very long in my experience with pt/pd.)

Sorry for all the questions, just trying to do the right thing...

Thanks,
Denny

Hi Denny,

It's all there at the Platinum printing manuals by this following authors:

Richard Sullivan
Dick Arentz
Luis R. Nadeau

12 years ago when I begun my long lasting and fascinating adventure in Pt/Pd printing, I've read all the books, manuals and texts I could get and I've got extremely confused because very often the approaches for the same thing were completely contradictory. Now, I accept this naturally and as a challenge for discovery.

 

[PVia]

I'm a bit confused in reading the last posts, it seems as though you expect potassium oxalate to be acidic, but I've just mixed up a fresh batch of plain po and I'm getting a pH of about 7.2. I've never seen any recipes that call for acidifiying po, or adding oxalic acid to po. I do remember an old thread on replenishment that indicated that the developer should be kept acidic at about pH 6. Are there any references to this in any literature or is this a recent trend?

I've always added some oxalic acid to get the pH to around 6.

I may be wrong but I believe it has something to do with the potassium carbonate being mono or anhydrous, and not knowing the water content of the anhydrous.

Kerik may be able to chime in on the reason. I believe I took my cue from him when mixing up my very first batch.

 

[Kerik]

Pt/pd is an acid-loving process. The pH of ferric oxalate is around 2.0. For best results we acidify papers that are too buffered out of the box. So, it stands to reason that the developer should be acidic as well. I can't explain it based on the mono or ahydros issue, but I've been printing pt/pd for nearly 22 years (holy crap I'm getting old), and from experience I know that a somewhat acidic developer works better. Add oxalic acid until the pH is around 6 and you're good to go.

 

[DennyS]

Thanks for all the feedback folks, I'm on my way to get some oxalic acid now...

 

[cabestan]

Hi Denny,

If I remember correctly, an acidic developer reduces the risk of formation of iron hydroxide from residual ferrous iron. Hydroxide which binds to cellulose so well that it is almost impossible to remove (yellow staining).

So, it is better to add some oxalic acid to potassium oxalate developer (or citric acid for sodium citrate) and to check regularly the pH of the developer which may evolve with usage (pH around 6 should be fine).

 

[DennyS]

Laurent, thanks for that explanation, it makes sense to me.

 

[jkschreiber]

This is interesting: I am just about finished printing a portfolio (that should have been finished years ago, but that's another story), and have run short of paper. I bought 250 sheets of 11x14 COT320 (the excellent batch 5212) for this project in the fall of 2009 but I think I must have used some of it for something else last year and have come up 20-25 sheets short.

So I just opened up a package of 22x30 COT320 (batch 5207) to cut down a few sheets and just as I'm about to put the first sheet into the Rototrim I notice there is a watermark which reads ... (drumroll) ... Arches Platine.

Of course I am aware of the speculation that the COT and Platine were made from the same stock and possibly on the same molds, but I guess this confirms the suspicion. This paper is still ever-so-slightly creamier in color than the Platine that I have on hand, which is consistent with past experience. It also has trimmed edges like COT, rather than the deckled/torn edges of Platine.

I'll see how it prints tomorrow.

~ Keith

 

[PVia]

Keith, just curious when and where did you buy the 22x30 batch?

 

[jkschreiber]

Hi Paul,

Purchased the paper from B&S in the summer of 2009. In digging through saved receipts to find that I also discovered that rather than 250 sheets of 11x14, I only bought 150 sheets. I guess that explains why I came up short.
Unfortunately, almost all of the prints I made yesterday on the cut down 22x30 sheets from batch 5207 have a spot or 2. I had no trouble with spots from the 5212 batch. The 5207 also seems to be slightly more absorbent.
I have about 10 sheets left of some 16x20 purchased at the same time, though I don't know the batch number since I didn't keep the wrapper. I'll try that next.

I called Dana at B&S yesterday and he said he had not heard any other similar reports but that it was his understanding that the 2 papers did indeed come off the same molds. Has anyone else seen an Arches watermark on their COT?

~ Keith

 

[PVia]

Not sure why but I've always had better luck with citric acid than oxalic for pretreating Arches. The 90# is nice for POP platinum and kallitypes. Doesn't seem to really need the prebath for kallitypes, but ziatypes are pretty weak without it. Not sure about DOP platinum.

The paper does seem to have a very slight red bias though, not as neutral as BFK or FAEW, even the 140lb bright white Arches. I've wondered if that tint has something to do with the citric acid. If you have any luck with oxalic and this paper I'll be very interested in it.

Colin, I made a print with the oxalic acidified Arches 90#, pure palladium with a hint of NA2...beautiful results, slightly less speed than Fabriano EW, but the real surprise was Stonehenge (white). Beautiful range of tones, great dMax, separation and a nice warm color. Very rich print, IMO. This paper was also acidified.

My previous batch of Fabriano, even when acidified and re-acidified, does not reach the richness and depth of the Stonehenge.

 

[Colin Graham]

Thanks for the info Paul. I keep forgetting about Stonehenge, really need to try it.