Re: Averaging profiles?
Re: Averaging profiles?
- Subject: Re: Averaging profiles?
- From: colorcanuck <email@hidden>
- Date: Wed, 26 Jan 2005 11:43:34 +0700
>Douglas Rhiner wrote:
>
>Would it make any sense to average profiles for media?
>Is this possible?
>
>For example:
>We print on quite a bit of canvas.
>We have a profile for our printer-media(canvas) combination.
>By nature the manufacturing process of the canvas we use results in what
>I call "qualitative drift" in each roll provided to us. Not a noticeable
>difference to the every day person, several others in the industry
>concurr with my observations.
>
>Regardless of time & effort invilved, would it be beneficial to print
>test/profiling patterns at the beginning of each roll, create a profile
>and then average this with the previous profile thus creating a running
>"average" profile for this media?
>
The "qualitative drift" is real from production run to production run. Each manufacturer has it's own QC (quality control) percentage of drift allowed as in any industry manufacturing industry.
We (I) would print measure targets on two (three if time allowed) of each lot number, measure and then average the data using ProfileMaker's MeasureTool averaging function, averaging two into one data set and then averaging one against the first averaged two. Over two years this allowed us to target legacy files and current files to within the same parameters.
Profilemaker's compare function allowed us to see the drift from any lot number to current lot numbers. It also allowed us to show our supplier that certain lot numbers (in particular the substrates) were unacceptable because occasionally OEM'd products change suppliers and don't change the packaging or tell the end-users. It is obvious to notice some substrate differences but when the dE steps way out of the previous range you can usually assume something is up.
Quality media providers generally provide better QC, just as quality suppliers will accept demonstrated returns based on data.
I should note that quite often for canvas and art paper the first two wraps of any roll are often not suitable for measuring. Check the beginning of your roll against the center for each brand and that will help ensure stability in your profile averaging. Ageing (and discoloration) seems to strike the beginning and ends of each roll of some manufacturers more than others. After some time you begin to see the differences between premium and third party economy brands.
It is well worth your time to average data from the previous lot and compare this to a profile averaged from earlier lots. (Methods of measure, software and hardware do play a role here too. Bear in mind their is a certain amount of subjectivity and, for some, methodology which go into organizing and determining which data sets to average.
Good luck...
;0)
--
joel johnstone
Color Canuck
(A lesser-known of the Bangkok joels)
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden