Grayscale printing on iP4000 - cost and actual ink used.

[drc023]

I've seen numerous discussions about grayscale printing on the iP4000 and whether or not pigment black and/or photo black is used vs composite black from CMY. I hope the following clears up some questions.

Tonight I printed 13 sheets (all were 8x10) using Photo Paper Pro settings on my iP4000. The photo was a scanned portrait image in grayscale of a little girls face. There was a fair amount of solid black background and then grayscale for the face and hair. Prior to starting the prints I topped off the existing HobbiColors cartridges that I had in the printer. I also have a small electronic scale that is accurate to 1/10 gram which I used to weigh the tanks before and after the nozzle checks and deep cleaning cycle. After printing I weighed them again and these are the results.

deep clean & 13 8x10
initial 2 nozzle checks prints
weight used used
Cyan 28.9 28.4 (.5g) 27.2 (1.2g)
Magenta 26.0 25.4 (.6g) 24.1 (1.3g)
Yellow 26.5 26.1 (.6g) 25.0 (1.1)
Photo Black 24.1 23.7 (.4g) 23.1 (.6)
Pigment Black 43.2 41.4 (1.8g) 41.2 (.2)

Total Ink Used for the 2 nozzle checks and one deep clean was 3.9 grams.
Total Ink Used for the 13 8x10 prints using Photo Paper Pro setting was 4.4 grams.

I was surprised to see any usage for the pigment black. While it is slight, the results do show that a small amount is used even when a setting other than plain paper is used.

What does this prove?
#1 Grayscale uses composite black along with a small amount of photo black and maybe some pigment black. This will hopefully resolve some of the questions about what inks are used printing grayscale.

#2 The cost per sheet is tiny. The following numbers are based on the current cost of HobbiColors ink from their eBay listing. $21.95 + $5.70 s&h = $31.85 I deducted the value of the five virgin ink tanks which is $9.00 and that leaves a net ink cost for the entire kit of $22.85. The kit has six 2oz (60 gram) bottles of ink for a total of 360 grams which makes the cost per gram to be .063472 Based on total ink usage for the the 13 8x10 prints it cost me 27.93 cents or rounded up to 28 for all the printing. This works out to be 2.15 per sheet.

#3 A deep cleaning cycle doesn't use very much ink.

Note that these numbers are not estimates. They are based on the exact weights as measured before and after printing.

Ron

 

[hpnetserver]

Wow! what an excellent work done! Question: did you notice any cleaning cycle excuted by the printer when it was printing the 13 photos? The printer invoked cleaning cycles might be the reason why the pigmented black ink was consumed but only a little. Great work, Ron.

 

[Nifty]

Yes, definitely an excellent post, and hpnetserver, I was thinking the EXACT same thing.

 

[Grandad35]

Look at the 4th photo in (http://www.nifty-stuff.com/forum/viewtopic.php?id=161), and the description immediately above the photo. The printer apparently periodically runs "mini-cleaning cycles" even in the middle of a print by spraying ink directly into the waste pad at the far left and right edges. It is possible that the pigment ink wasn't used to print or in "conventional" cleaning cycles, but was used during these mini cleaning cycles.

 

[drc023]

I didn't notice any of the periodic cleaning cycles during the printing, but that may be a result of the deep cleaning cycle which I ran prior to starting the print. It's entirely possible the mini cleaning cycles Grandad mentions are what caused the pigment ink usage since I know that pigment ink isn't used if not in plain paper mode. Next time I have a long print run (much more than the 13 sheets this time) with a variety of photos I plan on conducting the same tests. My oldest daughter also prints about 60 to 75 full sheets (borderless) at a time on her iP3000 and that should also give some interesting numbers. While the numbers from this test prove that composite black is dominant vs. photo black in grayscale printing, using a large sample of color photos and many more sheets will give a more accurate picture of overall ink consumption and the savings which result from refilling.