Ink Usage calculation based on coverage area

gjk008

Member
Hi,
I have searched the forum and found one formula for the Ink calculation based on the area of coverage, which is nothing but SPANKS formula.

Does any one have any idea how actually the Ink used is calculated wrt the area of coverage on the layout.

Thanks & Regards,
GJK
 

D Ink Man

Well-known member
Here is the most simple I believe the beast for lithographics inks: This has been utilized for many a moon now. Here it is. 1) 8.5" x 11" (93.5 square inches) sheet Coated Paper - 100K impressions Solid Coverage will use 30 pounds. 2) 8.5" x 11" (93.5 square inches) Offset Paper will use 45 pounds.

This is a tried and proved simple method. Of course you will caculate the coverage based on solids, halftones and size of the printed sheet based on the above caculations. Keep in mind, higher specific gravity inks, such as metallics will use more and lower specific gravity inks with low pigmentation will use less. This is a basic generalization. Try it and see what your current mileage estimate comes out versus any other caculation you might use. I believe that once utilized on multiple estimates, you might thank me one day. D
 
Last edited:

kevrich

Member
I will agree with D Ink,

If you figure the total area (sq in) of solid printing then multiply that by total impressions, then divide that number by 375,000 (sq in per pound of ink) will give you a estimate of ink needed. The pound per square inch is the biggest variable. You may get 450,000 sq in from a pound of ink, but on the other hand you could get only 250,000 sq in per pound.
 
Ink Usage calculation based on coverage area

It seems to me, being a student of ink usage... There are multiple factors that must be considered. As a packaging printer, we use from Litho sheet, to SBS, to Coated board. The factors (mileage per pound of ink) are significantly different. This should be a key element when figuring ink usage. I am currently working with Prinergy and there are capabilities in the engine of generating an ink report when we impose our files and send the CIP information to press. I receive the sq inches for each color, perhaps your prepress workflow may have some of these elements too. Some of the figures i receive range from 200 sq inches to 22 sq inches so it has been very helpful. I also like to consider waste ink, or makready ink as another factor for estimating ink usage: MR, Run-up, and contaminated ink for example. I am annoyed by how much ink is left on the shelf, but it's better to have half a can over than half a can short.
Another tip is to have your ink vendor run a mileage test on your substrates with each version of ink that you use. Vendors should support in every way.

My formula FYI:

(sq in coverage for each color x impressions x waste / usage factor)

CA
 
Usage factor:
(Conventional Ink)
800,000 for Coated Paper
650,000 for SBS
800,000 for Plastic
(U.V. Ink) -
500,000 SBS
600,000 Coated Paper
650,000 Plastic
 

gjk008

Member
My formula FYI:

(sq in coverage for each color x impressions x waste / usage factor)
Usage factor:
(Conventional Ink)
800,000 for Coated Paper
650,000 for SBS
800,000 for Plastic
(U.V. Ink) -
500,000 SBS
600,000 Coated Paper
650,000 Plastic


CA[/QUOTE]

Hi,
Is there anyway i can get the usage factors for different kind of boards, SUS,TBC,CCNB etc for CMYK color Inks, Mettalic Inks, Spot Color Inks.

In the formula, if i do not know before hand how much is my wastage how should i proceed?

Thanks & Regards,
GJK
 

gjk008

Member
1) 8.5" x 11" (93.5 square inches) sheet Coated Paper - 100K impressions Solid Coverage will use 30 pounds. 2) 8.5" x 11" (93.5 square inches) Offset Paper will use 45 pounds.

D

Hi,
How would i know for what kind of paper and what kind of coverage the poundage will be.
That means you need to have a table where you have all the variables i.e
Type of paper, Type of Coverage, Number of Pounds of Ink Consumed. given the constant area of coverage.

My situation is I need to cost the Ink that is being used up in the printing process,

I know the type of board being used.
I know the area of coverage(%age) that will be printed per Ink color.

I need to calculate the Poundage of Ink used for that particular area for that particular board.

Depending on the poundage i can calculate the cost of Ink.

If i can get the formula for Poundage of Ink consumed Depending on the above parameters that would be great.

Any idea on how i can derive the solution for this situation, will be greatly appreciated.

Thanks & regards,
GJK
 
Being how we have just installed a new press (kba 106) we are still adjusting to the print-ability factors in our manufacturing process.

I actually had a job that was ccnb, used an ink factor of 650,000 and realized that I ordered half the amount required. Would I use 325,000 for my next ccnb job??? I think, along with discussion with other about this issue, that it does take some trial and error, but definately, I will use 450,000 for my next ccnb job and see where we end up.

Hope this thought helps with figuring the mileage characteristics for TBC and SUS. Create a benchmark and then adjust, best to do this with your vendors and not someone elses.


CA
 

Bob Peterson

Well-known member
For what it's worth, I have found the attached pdf a useful guide when estimating ink usage.
 

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  • Ink Estimation.pdf
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herbert

Well-known member
'I am currently working with Prinergy and there are capabilities in the engine of generating an ink report when we impose our files and send the CIP information to press.'

Hi There

Can you explain how to get hold of the cip file. How do you read the data in the cip3 file to get hold of that info. (we have prinergy_

Thanks


Dan
 
My understanding is that the Ink Usage data will be provided to your printing press via CIP3, after the file has been imposed. This data is stored in the Prinergy user folders (I think under Ink Reports, if my memory serves me correct).

This information is the result of square inch coverage over the press sheet for each color, including any spot color or coating plate.

So, they give you an estimate of the square inches of ink being layed down on the press sheet, now what I did is used a simple formula:

(Sq In x Impressions x waste % / Ink Usage Factor)

This would then translate into the number of Pounds that would be estimated for the job for each ink.


This should work, be liberal on the start up, then dial it down and try to capture your variation per each job.


Charles
 

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