I use Paint Pro, and so there is no ink cost information when I print. Anyway, I'm not sure if those values from the RIP are trustworthy. Do you think they are?
Anyway, I carried out a test to figure out ink consumption. This is how I did it:
1) I created a 20x20cm (7.9x7.9 inch) square, 100% magenta.
2) I accurately markt the ink level of my magenta bottle (also the others, just in case), and used a syringe to add exact 10 ml of ink to the bottle. My idea was to see how many prints I could do with these 10 ml.
3) I printed this square over and over again on a some white t-shirts, resolution 1440x1440.
4) I extrapolated the results to figure out the overal ink consumption. Now this is the tough part, and would like your opinion to see if this make sense at all.
Result: 8 exact 20x20cm prints from 10 ml of ink.
if 1 liter (1000 ml) of ink, let's say, cost $300 => 1 ml = $0.3
10 ml => $3, so $3/8 prints = $0.375 per print (cmyk at 1440x1440)
Here comes the big question:
if we set t = 0.375 as the CMYK cost, in order to deduce the WHITE cost of such a print, should it be 4t (4 times t)? I say that because white has 4 injectors, and 100% magenta, just 1.
So, if wanted to know how much would be the same magenta square 20x20cm with white underbase at a resolution 1440x1440 white and 1440x720 cmyk, my right formula should be 4t + t/2?
If so, 4x0.375 + 0.375/2 = $1.6875 for a 20x20cm (7.9x7.9 inch) with white underbase. Correct? Wrong?
If this is true, if we have white highlights on the print at 1440x720, should they factor as 2t (4 times t/2)? (for the same reason, 4 injectors firing 1440x720)
At the beginning I thought that it would be enough t + t/2, but this amounts only $0.562 and seemed to me too nice to be true =)
My final goal of all this calculations, is to know the square cm cost of a print. With this and knowing the exact surface of a particular design, the total cost can be known BEFOREHAND.
Btw, does the dpi resolution affect on how much ink is layed down (for example, 72dpi vs 300dpi)?
I think you may be trying too hard here. Safe to assume that it costs about 25-50 cents for a light shirt and $2.50-4.00 for a dark shirt. Of course these will vary somewhat, but 90% of the full front shirts you print will be in this range (assuming $300 per liter ink cost).
Albert
Best way to measure and accurate is weighting. Not volume.
Print any squire size you want on many color or single or any DPI but you have to know your printing area exam: 100sq" or 60sq".
take weight all you cartridges (A) (with ink in it)
After finish print weight again (B)
Formula is
(A-B)/sq" = will tell what is your usage by weight. DuPont ink weight is 1ml = 1.05g on color.
I hope it clear your question. You need GOOD Scales as we use in our lab.
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take weight all you cartridges (A) (with ink in it)
After finish print weight again (B)
Formula is
(A-B)/sq" = will tell what is your usage by weight. DuPont ink weight is 1ml = 1.05g on color.
I hope it clear your question. You need GOOD Scales as we use in our lab.
Unfortunatelly, I can't weight my cartridges, since I'm using the HM1 with WIMS2, and I can't do that with the white :-)
But a lot of my question would be answered if anyone could afirm, if teorically white underbase uses 4 times more ink that the same resolution for CMYK... or not.
I totally agree with elTostador here. What he is saying is that once he knows how much a sqInch costs he can then examine the art in photoshop and determine an actual live quote.
I have an idea for you elTosador; Take a piece of cling wrap and weigh it. Cover your board with the cling wrap. Print a 1"x1" square of white on it. Weigh it again. Then you can remove the 10mL of white with the syringe and weigh that too. I'd suggest weighing the syringe empty first, then pull in the 10mL and weigh. You can repeat that process with the magenta to check your initial results.
Then in photoshop you can split your channels and force to bitmap. Once in there you can get the total pixel count and the black and white pixel counts. Use the black/total pixels to get your % coverage. Then calc the total sqInches of that design and viola, you have your sqIn of coverage for that channel. Repeat for CMYK and you can accurately calc that cost. For white you can probably take your design, force to greyscale then invert, then force to bitmap and do the same black/total to get your % coverage and then quickly get your usage of white as well.
Figuring a square inch cost does not give an accurate answer to what full color graphics will cost. The amount of ink laid down in a square inch will vary depending on the color printed as well as the resolution. Inks are sold by volume, not weight. The only accurate way to measure the cost is to have software that calculates the volume of ink printed and then multiplies this times the volumetric cost of the ink.
That is why you need to find the total square inches of ink coverage for the design. You can do this in photoshop. So lets say you have a line of text that is red. It uses magenta and yellow and white. It's 4 inches tall and 10 inches wide. So 40 square inches of area for the whole design. Then we check the magenta channel and see that the pixel count for the magenta channel shows the black pixels make up 50% of the total area. So that means that there are 20 square inches of magenta put on the shirt. Do the same for yellow ect. For the white you can probably use a grayscale of the image and find the pixel coverage %. Then you multiply corresponding square inches x cost per square inch.
What if it uses shades of ink or gray or brown? Ink coverage will vary greatly based on the amount of ink printed. 100% cyan and 100% yellow for instance can be measured, however, most images are not 100% mixes of colors, so it would require some sort of mystical math to come up with an accurate amount.
In all that time calculating, you could have been printing and making money. You will never use more than .40 cents on a 14x14 CMYK, the rest doesn't really matter does it?
And as far as the white goes, It isn't just the ink you are laying down on the shirt, you also have to take into concideration all the cleanings needed to keep the white flowing. There isn't an Epson based printer out there that doesn't need a power clean now and then to get the white nozzles all firing again, especially if you leave it sit for a couple days. And leaving white ink sit for any length of time at all in the system causes it to separate, then you have to purge the lines before printing. My point is white ink calculations can be all over the board.
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factor in a maximum ink cost of $0.50 for CMYK and say $3 for white. always apply this amount as a fixed cost, you wont get any nasty surprises that way
Figuring out ink costs with my HM1-C 
