baryta paper storage and icc profiles

[alain]

Hi

I'm thinking of buying some "Ilford Gold Silk" and get myself a custom profile made.  I won't use lots of it and so the paperstock will last quite some time (probably between 1 and 2 years).  This raises some questions for me:

Is the unprinted paper stable when kept in it's original packaging, although there are taken some papers from time to time, aka its been open and will be reopened from time to time? It would stored flat at "normal" room conditions.

Is there a "de facto" expiration period on custom made profiles?


If I buy from different lot's (let's say every 3-6 months), could the profile be valid, or is the difference to big in most cases?



Alain

[alain]

Is this such a difficult question?

[Geoff Wittig]

Hi

I'm thinking of buying some "Ilford Gold Silk" and get myself a custom profile made.  I won't use lots of it and so the paperstock will last quite some time (probably between 1 and 2 years).  This raises some questions for me:

Is the unprinted paper stable when kept in it's original packaging, although there are taken some papers from time to time, aka its been open and will be reopened from time to time? It would stored flat at "normal" room conditions.

Is there a "de facto" expiration period on custom made profiles?
If I buy from different lot's (let's say every 3-6 months), could the profile be valid, or is the difference to big in most cases?
Alain
[a href=\"index.php?act=findpost&pid=174921\"][{POST_SNAPBACK}][/a]

I'm guessing the problem is that nobody knows the answer. One would hope that, given the image stability claimed for inkjet prints, the papers themselves are stable before printing. I have noted that some of the newer fiber/gloss sheet papers do seem to take on a bit more curl once they've been opened, so I suspect they're absorbing a bit of moisture from the air. I haven't noted any color drift over at least six months of printing from the same box, but that's just me; I'm no expert.

For what it's worth, Bill Atkinson's profiles for my Epson 7600 still seem to be accurate enough to my eye more than four years on, but then I'm not measuring color patches or doing super-critical work. I worry more about manufacturers changing the characteristics of a given paper than a profile "expiring".

[Ernst Dinkla]

Is this such a difficult question?
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You didn't find an answer yourself in that period ? :-)

Two ways to make an ICC profile worthless in two years:

The printer isn't consistent in time and can not be calibrated to the condition at the time the profile was made, printer goes dead and/or will be replaced for other reasons.

The paper varies between batches and the printer can not be calibrated to that variation, the paper is no longer produced, the paper (from one batch !!!) you stored has changed in condition.

So if you go that route you have to make sure you get paper from one batch. Store the paper at 55 % humidity average, sealed polyethylene bags will slow humidity variations within so there may be some variation outside. Long periods of high humidity + high temperature could create mold in gelatine or PVA coating binders.
Low humidities excessive curl. Changing humidity can create waves in the paper that are harder to straighten.

There may be a new even nicer paper that gets your preference.


Ernst Dinkla

try: [a href=\"http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/]http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/[/url]

[Marty C]

Ilford has gone to extreme care in its packaging of the Gold silk. The paper comes in a white resealable internal envelope which I feel will give complete protection from outside elements like moisture, dirt ect.

I feel they did their homework before putting this product on the market and I would not be afraid to say it will look just as good in two years as it does today.

[Brian Gilkes]

The paper has little to do with how the ink is received., although texture contributes. The coatings are the main factor; both their chemical constituents and their thickness.  This seems to be a mature technology with a history far predating digital printing. In my experience over the last 5 years with inkjet papers , and some decades with their analogue predecessors,  I have found a very high degree of consistency. Occasionally their are coating faults resulting in streaks or patches of varying density, but in these cases colour does not seem to vary. In any case paper faults mean reprints anyway.
In practice I have not noted the need for reprofiling because of paper changes , and would not worry about this. I would be more concerned with machine head wear over time . Nozzles worn by pigment abrasion will become larger , delivering more ink . If nozzles from one colour wear more than the others , then colours will shift. I would expect this to be much more a concern with thermal heads (Canon, HP etc) rather than piezo (Epson , Roland etc.). It would be informative to thermal head users reported on test chart readings , say every few litres of ink use. That's the sort of thing we are not reading in the revues .
HTH
Brian
www.pharoseditions.com.au

[TylerB]

Brian, the one exception for myself and some others I know would be Photo Rag over the last year or two. We've seen quite a batch variance. When I get a new roll in, with a new lot number, I relinearize, then reprofiling is not necessary unless it can't reach it's previous densities or limits. That's a RIP thing though, reprofiling may have been required for an OEM RGB driver.
Other papers, even from the same manufacturer, have been very consistant as you suggest.
I haven't been through enough Ilford to know about it yet.

Tyler

[digitaldog]

Is there a "de facto" expiration period on custom made profiles?

Yes, never. Profiles don't age like cheese. The paper or the printer may undergo some change which would make the profile (depending on this difference) useless. But the profile itself doesn't change unless someone edits it.

As for the paper, who knows? As for the printer, those like Epson are incredibly stable devices. You didn't define a printer, only the paper. One would hope that a well made paper, properly stored and consistent in manufacture would allow you to use the profile for a very long time indeed.

[Ernst Dinkla]

The paper has little to do with how the ink is received., although texture contributes.
In practice I have not noted the need for reprofiling because of paper changes , and would not worry about this. I would be more concerned with machine head wear over time . Nozzles worn by pigment abrasion will become larger , delivering more ink . If nozzles from one colour wear more than the others , then colours will shift. I would expect this to be much more a concern with thermal heads (Canon, HP etc) rather than piezo (Epson , Roland etc.). It would be informative to thermal head users reported on test chart readings , say every few litres of ink use. That's the sort of thing we are not reading in the revues .
HTH
Brian
www.pharoseditions.com.au
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There's huge difference between paper coatings and what they can absorb properly. More in matte and less in gloss varieties. There are batch differences with Innova and HM coatings in my experience. There are texture differences in matte art papers even in batches as a result of the felt blanket on the foudrinier getting filthy and the texture rougher by it at the end. They do their best in the plants but there is some quality shift as a result of that. And rougher texture means that the paper coating is applied differently, one reason to lay down that coating in more than one layer.

The main inconsistencies with Epsons have been pigment settling, head clogs, damper clogs in my experience, all delivering less ink or color shifts. More ink laid down by wear on the head nozzles is not what I ever have experienced but with my Epson 10000 where one head suddenly went kaput and that was not a gradual process. With the HP Z3100 the consistency has been incredible over almost a year. I does ask for a calibration once a month but when I ignore it when in a hurry I do not see shifts. If a nozzle does not function properly it will be substituted with one in reserve after some cleaning trials. No head has been replaced so far though in that period. What you are not reading in reviews and messages on this board may well be because it doesn't happen. Normally mailing lists and forums like this are cluttered with problems and not with messages on trouble free printing. The HP issues are widely discussed here but no serious message appeared here about color shifts, clogged heads, abnormal head wear on Z models. On Epson lists it is a common topic.


Ernst Dinkla

try: [a href=\"http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/]http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/[/url]

[alain]

Thanks for the reply's.