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Miha
14th February 2012, 07:43 PM
I haven't been printing on RC for a while, two or three years probably, but my recent Ilford RC prints show much more curl than some old RC prints also made on Ilford stock. Wet time was probably around 30 minutes, as always. Has anyone else noticed this phenomena?

p.s. Fotokemika paper was always curly, but prints made on either Ilford, MCP, Kodak RC were always completely flat...

I have attached a photo showing a few too curly 5x7 and 8x10 prints (for my tastes, at least):

http://shrani.si/f/3V/TN/zzwqsr9/p1150542.jpg

Mike O'Pray
14th February 2012, 07:55 PM
If your process including drying is the same as before this looks serious. I haven't bought any Ilford paper recently but my old stock like yours shows no signs of curl. This only ever happened to me if I dried the paper with the heating element( intensive heat) switched on in my fan assisted drier and the curl disappeared in a matter of a minute or so if I finished the job by fan assisted air at ambient temp only.

I can't believe that Ilford has suddenly manufactured paper which is inherently as prone to curl as this.

Mike

Miha
14th February 2012, 08:05 PM
Prints were dried at room temperature. I've notice the curls to be more severe in the winter months when the central heating is on and the air is dry. The prints were made late in August and they looked fine at the time. Still, older prints that are kept under the same conditions show no curl.

Jon Butler
14th February 2012, 08:22 PM
Reduce your washing time to 2mins max, I'm sure that will sort it.
J.

Miha
14th February 2012, 08:37 PM
Reduce your washing time to 2mins max, I'm sure that will sort it.
J.

This would be too time-consuming for my workflow.

Mike O'Pray
14th February 2012, 09:00 PM
As Jon has said 2 mins is enough for RC prints but my experience on a nightschool course was that students, including myself would have a wet time of 30 or more mins without curl problems. To give us max time on the enlargers we all left prints in the water pool until the end of the session so in excess of one hour wasn't unusual.

However our prints were then sent through an Ilford rapid dryer, again for speed at the end of the session- there used to be a queue for the dryer before the tutor threw us out of the college so he could get home :D

Mike

JohnB
14th February 2012, 10:05 PM
I use Ilford RC and in my experience, it dries pretty flat. I wash them for about 4 mins in water at approx 20 degrees C and then hang them off the shower rail to dry at room temperature.

Just a thought, is the water you are using perhaps too cold?

Miha
14th February 2012, 10:23 PM
Just a thought, is the water you are using perhaps too cold?
No, I don't think it is. At least not in August.

Argentum
15th February 2012, 03:33 AM
Dry them face down.

Dave miller
15th February 2012, 07:59 AM
I suspect that this may be a question for Ilford since no one else is experiencing the same problem.

Richard Gould
15th February 2012, 02:57 PM
I use a lot of RC paper, Mainly fotospeed, which is made by Harman, and I have never had a problem with rc paper curling,
Richard

Miha
15th February 2012, 04:34 PM
Me neither, but I suspect the wet time was too long this time.

Richard Gould
15th February 2012, 05:29 PM
Miha, including time spent in a holding bath prior to a wash my wet time can be anything up to 45 minutes for some sheets, I wait untill I have 2 sheets to wash, that is, 2 finished prints, which with some images can take a while, I have had sheets in water sometimes for an hour or more, that includes Ilford, Fotospeed and Agfa papers over the years and I have never had any problems with curl, I always wash for 3 minutes, and dry my prints hanging on a line after gently wiping with a patterson RC wiper, in fact a few years ago I conducted an experiment with RC paper,(Multigrade) and washed the paper for a few hours, and upon drying no problem with a curl, although one or two sheets did start to de laminate,
Richard

Miha
15th February 2012, 05:51 PM
Thanks Richard, good to know. I will probably contact Ilford in the following days... and stick to FB

p.s. I also have some prints that are made on Kentmere RC (Harman made) from last spring that are absolutely flat.

arcr1
15th February 2012, 06:06 PM
Hi Miha,

The other thing that's odd is that your prints appear to have curled the opposite way to all the RC prints I've seen (both my own, and students on courses I've attended) on Ilford, Kentmere and Fotospeed papers.

Like everyone else who's commented so far, I've never had the kind of problem you report, and what slight curl there might be in all my RC prints has been the same direction that the paper has when you take it out of the packet to put it under the enlarger - i.e. the emulsion surface is convex, not concave as your prints appear to be.

Andrew

Argentum
15th February 2012, 06:13 PM
looks like drying the emulsion side too fast.

Miha
15th February 2012, 06:17 PM
looks like drying the emulsion side too fast.
It's RC. How could fast drying affect it? It was dried on newspaper sheets in my darkroom.

Miha
15th February 2012, 06:18 PM
The other thing that's odd is that your prints appear to have curled the opposite way to all the RC prints I've seen

I agree.

Argentum
15th February 2012, 06:36 PM
It's RC. How could fast drying affect it? It was dried on newspaper sheets in my darkroom.

What do you think actually makes paper curl, FB or RC?

Richard Gould
15th February 2012, 06:49 PM
looks like drying the emulsion side too fast.
Other than using one of the RC paper dryers, which you really don't need, it is almost impossible to dry RC paper too fast, I hang the paper on a line in my darkroom, and it air drys within ten minutes at the very most, sometimes quicker, and I have yet to have a curl problem, I can't say if dryers cause problems as I have never used one, but I have never heard of them causing curl,
Richard

Miha
15th February 2012, 06:50 PM
What do you think actually makes paper curl, FB or RC?

RC: reduction of polyethylene layer / emulsion / supercoat in size on one side compared to other

FB: swelling and drying don't happen equally in all directions (pulp, gelatine, baryta)

Argentum
15th February 2012, 07:12 PM
exactly, so if curl is on gelatin side it indicates that side has dried faster than the other side and in your case that means it stretches/pulls the paper fibres apart which then set with a curl in them. Dry face down which restricts airflow over gelatin and makes gelatin side dry more slowly which equals less curl. Weight of paper also reduces curl towards gelatin a little.
Can't harm to try it.

Otherwise get a Kindermann RC30 (Trockener 30) if you can find one. I think they just stopped making them.

Miha
15th February 2012, 07:24 PM
exactly, so if curl is on gelatin side it indicates that side has dried faster than the other side and in your case that means it stretches/pulls the paper fibres apart which then set with a curl in them. Dry face down which restricts airflow over gelatin and makes gelatin side dry more slowly which equals less curl. Weight of paper also reduces curl towards gelatin a little.
Can't harm to try it.

Otherwise get a Kindermann RC30 (Trockener 30) if you can find one. I think they just stopped making them.

But RC paper is sandwiched between two layers of polyethylene. The gelatine being coated on top of it. There's no paper fibres-gelatine interaction and no drying-related curl.

Miha
15th February 2012, 07:32 PM
There is also Nova: http://www.novadarkroom.com/product/107/Nova_RC_Paper_Dryer.html
but I don't do enough RC to justify it.

Argentum
15th February 2012, 07:43 PM
But RC paper is sandwiched between two layers of polyethylene. The gelatine being coated on top of it. There's no paper fibres-gelatine interaction and no drying-related curl.

It must be curly PE then :rolleyes:

Mike O'Pray
15th February 2012, 07:47 PM
There is also Nova: http://www.novadarkroom.com/product/107/Nova_RC_Paper_Dryer.html
but I don't do enough RC to justify it.

I have one but it was bundled into a set of stuff I bought secondhand. The new price seems ridiculous. They used to come up secondhand on e-bay but supply seems scarce now.

It's a pity you are so far away Miha. You occasionally see the Ilford heated roller dryer as a collect only secondhand item on the U.K. e-bay as it is quite big and very heavy. It does wet to dry in seconds only and is a bargain compared to the new price of the Nova model

Mike

Argentum
15th February 2012, 07:49 PM
There is also Nova: http://www.novadarkroom.com/product/107/Nova_RC_Paper_Dryer.html
but I don't do enough RC to justify it.

I have one of those which I don't use if you want to buy one but the Kindermann is a better unit as it uses radiated heat rather than blown hot air. The Kindermann is similar to the old Ilford units. The benefit of them is that they produce a very high gloss finish which the air blown ones don't. If you are not using gloss paper then I guess it makes little difference. Having said that, if you are getting curly prints something is causing it and heat may not be a good idea.

Miha
15th February 2012, 07:58 PM
Thanks for your input, but I prefer simple things, like newspaper sheets :)
I find things like dryers and 'archival' washers redundant. A good easel and a good stop clock is all I need.

Richard Gould
15th February 2012, 08:36 PM
I think that unless you were printing RC at commercial levels then these dryers are simply not needed, indeed, that is what they were designed for, and if you are having curling issues then the heat would only make things worse. Personally I find RC paper dries quite fast enough hanging on a line it is dry in a matter of minutes.
Richard

Mike O'Pray
15th February 2012, 08:59 PM
Personally I find RC paper dries quite fast enough hanging on a line it is dry in a matter of minutes.
Richard

Miha uses ambient room temp drying as well which seems very similar to a hang on a line method and has done this room temp drying previously without problems.

I am not sure we have got anywhere near getting to the problem's cause on a collective basis

I am inclined towards Dave's suggestion that contact with Ilford is worthwhile.

Ilford always seems keen to get to the bottom of any potential quality issues and this may be one

Mike

Richard Gould
16th February 2012, 08:09 AM
Miha uses ambient room temp drying as well which seems very similar to a hang on a line method and has done this room temp drying previously without problems.

I am not sure we have got anywhere near getting to the problem's cause on a collective basis

I am inclined towards Dave's suggestion that contact with Ilford is worthwhile.

Ilford always seems keen to get to the bottom of any potential quality issues and this may be one

Mike
I would also say that they only way to get an answer is an Email to Ilford, as I can't see an answer to Mihas problem, it is just a poslbiltity that there is some QC problem, very unusual with Harman, but I can't see anything else other than a problem with the paper itself, and I am sure Harman will do everything in their power to sort the Problem out. It will be interesting to find out what is happening.
Richard

Dave miller
16th February 2012, 08:18 AM
Drying speed is a factor of low humidity rather than temperature. Due to the very cold weather in Europe over the last moth I suspect that the humidity is very low so allowing very fast drying. Since humidity falls as temperature rises this effect is exacerbated at room temperature. I suggest that these prints are washed for a few minutes and then hung to dry in a room with standing water, such as a bathroom with water in the bath, this should slow the drying to closer to more normal rate.

Miha
16th February 2012, 09:11 AM
Dave, these prints were processed in August. Prints made on Kentmere RC were also processed last year and are OK. I shall contact Harman in the following days and report back to you.

Dave miller
16th February 2012, 09:43 AM
Dave, these prints were processed in August. Prints made on Kentmere RC were also processed last year and are OK. I shall contact Harman in the following days and report back to you.

OK. But you did say "recent" in your opening post. ;) Never mind, Ilford it must be then.

Miha
16th February 2012, 09:59 AM
OK. But you did say "recent" in your opening post. ;) Never mind, Ilford it must be then.
True! How time flies... :)

Dave miller
16th February 2012, 10:07 AM
True! How time flies... :)

Don't remind me, I still think I'm a teenager. :shock:

Roger Cole
16th February 2012, 11:53 AM
Humm, all my RC prints curl, though usually not this much.

Hi Miha,

The other thing that's odd is that your prints appear to have curled the opposite way to all the RC prints I've seen (both my own, and students on courses I've attended) on Ilford, Kentmere and Fotospeed papers.

Like everyone else who's commented so far, I've never had the kind of problem you report, and what slight curl there might be in all my RC prints has been the same direction that the paper has when you take it out of the packet to put it under the enlarger - i.e. the emulsion surface is convex, not concave as your prints appear to be.

Andrew

Mine curl, and they curl in this direction, just not this much. I wouldn't call it a problem though. I don't really care. If they're mounted or framed they're fine, and if not, well, so they're curled a bit. ;)

I've also found that using heat will STOP this. I learned this years ago printing color. I'd use a hairdryer to dry test prints so I could evaluate the color, as the color is way off until they dry. I found my test prints would lay flatter than the finished prints that I air dried. At the time, anyway, I also found this to be true with black and white RC, but I confess I haven't tried it in something over a decade so I don't know if it's still true of current papers.

In college I was really bothered by curl or unevenness/waviness in FB prints. Then I started hanging out with some folks who didn't seem bothered by it, and I think I eventually picked up their attitude. If you can't flatten 'em, don't worry about it.

Probably not very helpful, I know. ;)