View Full Version : Proofing Standard
PeterArnel
11-14-2005, 01:48 PM
I am sure everyone is interested in this!!!!!!?????
There is a big change afoot in the way colour is managed in printing. Up until now the current thinking is - that we calibrate our proofers to match our presses. Which seems sensible but is flawed. Now with this new ISO standard jobs are proofed according to the standard and we adjust the dots on our plates and our ink densities on our presses to match it. This is much better. Our customers can now get their jobs proofed on any calibrated proofer (Epson etc)any where in the world ( these can be checked by measuring a control strip with a spectrophotometer) WE also have a measurable colour standard to work to.
Peter
And if people dont yet know what LAB colours are - find out -Pantone are now measuring their colours in it.
Robin Springall
11-14-2005, 02:51 PM
Anything that improves the current situation is a welcome sign. One printer we used made matchprints for signing off, then kept on producing print that didn't match the proof colours. We eventually found out that the proofs never made it into the machine room!
Craig
11-15-2005, 05:48 AM
I am sure everyone is interested in this!!!!!!?????
There is a big change afoot in the way colour is managed in printing. Up until now the current thinking is - that we calibrate our proofers to match our presses. Which seems sensible but is flawed. Now with this new ISO standard jobs are proofed according to the standard and we adjust the dots on our plates and our ink densities on our presses to match it. This is much better. Our customers can now get their jobs proofed on any calibrated proofer (Epson etc)any where in the world ( these can be checked by measuring a control strip with a spectrophotometer) WE also have a measurable colour standard to work to.
Peter
And if people dont yet know what LAB colours are - find out -Pantone are now measuring their colours in it.
Where would I be able to read up on these? You know it takes a little bit for that kinda stuff to float across the pond :).
Michael Rowley
11-15-2005, 07:01 AM
Craig:
You know it takes a little bit for that kinda stuff to float across the pond
The Lab system is just a modification of the original CIE system (1936!) and is well known in America—in fact most of the textbooks that discuss it are American.
PeterArnel
11-15-2005, 11:47 AM
Criag - I dont have a real source and have just put LAB Colours and searched and found lots of sites. LAB is a way of measuring colour on a spectrophotometer and every colour has a LAB Number
PeterArnel
11-15-2005, 11:48 AM
I just dont know why u dont use a decent printer
Peter
If I knew one I would recomend one
Michael Rowley
11-15-2005, 12:27 PM
Peter:
have just put LAB Colours and searched and found lots of sites
If anyone looks for 'cielab' in Google he will get lots of relevant hits on the first page he looks at, including one from the American printing journal (I have forgotten which one) explaining the virtues of using CIE Lab instead of RGB or CMYK. The CIE site isn't very helpful to non-experts.
The original CIE system dates from 1931, but better measurements (at 5 nm intervals, instead of 10 nm) led to better appreciation of colour differences and the develoment of the 1976 L, a, b system of specifying colour in three dimensions.
Adobe has used the system for years: it's not at all new, and well known everywhere.
PeterArnel
11-15-2005, 01:31 PM
Michael - I am not to sure about well known everywhere- but you are right that its not new. However its like all things - it will soon be the in vogue word in colour
Peter
Michael Rowley
11-15-2005, 02:28 PM
Peter:
I am not too sure about well known everywhere
It is to colourists: I wouldn't know about printers! To be honest, the original CIE coordinate system is better understood by me, but I translated stuff about the L, a, b system shortly after it was published. I don't know what the practical advantages are that led to the choice of that system rather than the alternative L, u, v or straight trichromatic systems, but all three are inter-convertible and absolute systems, as opposed to the RGB and CMYK systems.
The system would be no use without modern instrumentation, which is why its practical application since 1976 has not been as rapid as it might have been. In 1982, when I left BASF (which makes many of the pigments used today), the colour technicians were still describing differences between various samples of blue (say) as, 'a tinge redder', 'a tinge greener', although BASF was not short of instruments: at that time, the schooled eye distinguished colour differences better.
Most of the modern spectrophotometers are made in America (or Japan), and presumably sold there.
PeterArnel
11-16-2005, 07:09 AM
THanks Michael - The Spectro used these days are Gretag - I dont know who makes them
Craig
11-16-2005, 01:10 PM
Thanks for the info guys! I am trying to get by being self taught so every little bit helps, kinda like a sponge. So far so good!
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