Ink Costs

[Peter McLennan]

Why are carts opaque?  If they were transparent or translucent plastic, we could see exactly how much ink remains and most of these issues would be moot.

Kinda reminds me of the apocryphal story of the NASA space pen and the Russian space pencil.

[Farmer]

The bags are opaque within the cartridges as well.  Both to protect against exposure to light (UV, etc).

[Alan Goldhammer]

The bags are opaque within the cartridges as well.  Both to protect against exposure to light (UV, etc).

Though this is curious since the cartridges are already double packaged and when inside the printer not exposed to light.  That being said, even if there was a translucent side to the cartridge it would still be difficult to tell how much ink was left given the overall design (the bag that holds the ink collapses as ink is delivered to the printer).  The only reliable way to do this (if you don't want to believe the printer's ink indicator) would be to periodically take the cartridge out and weigh it (which would be a real pain in the behind).  Since ink costs are low relative to the cost of paper, just don't worry until the cartridge runs out of ink and needs to be replaced.

[Mark D Segal]

If you are selling printing as a service, the cost of ink is an important variable. If you are selling prints it isn't - or at least shouldn't be.

In either case, given the difficulties that exist in micro-measuring consumption, the total inventory approach is really the most practical way of understanding ink costs. We do have total control over knowing the number of square feet of ink coverage we have commissioned from our printers. Keep a record of that in real time. We do have control over knowing how much ink we have bought and consumed in total for the concerned printer - keep track of that, using the information from the printer for an estimate of ink remaining in the tanks. Subtract the remaining ink in the printer and in inventory from the total starting and purchased volumes, and we know reasonably well how much ink we have consumed. At some point after quite a few square feet have been printed (I recommend several hundred), divide the square footage printed into total net ink consumption and you have a decent measure of ink usage per square foot, combined for printing and maintenance. Since both are essential for producing a print, they don't need to be separated to understand total ink cost per print.What we then do with that information I don't know, unless one is printing as a service - in this case it gives decent insight into that element of the cost structure. For people selling prints, other factors will be far more important than the cost of ink.

[Ernst Dinkla]

It would not be so difficult to create a simple visual indicator actuated by the shrinking ink bag that gives a rough estimation of the cart content. Open an old Epson 9000 cart and it shows how it could be done. On the other hand most users will like a software graphic that shows all carts contents in one window, like it is today. On a big job with a chance an empty cart may reach bottom too early I will put in a full cart and exchange that cart again to empty the old one on small jobs.


--
Met vriendelijke groet, Ernst

Dinkla Grafische Techniek
Quad,piëzografie,giclée
www.pigment-print.com

[Jim Pascoe]

If you are selling printing as a service, the cost of ink is an important variable. If you are selling prints it isn't - or at least shouldn't be.

In either case, given the difficulties that exist in micro-measuring consumption, the total inventory approach is really the most practical way of understanding ink costs. We do have total control over knowing the number of square feet of ink coverage we have commissioned from our printers. Keep a record of that in real time. We do have control over knowing how much ink we have bought and consumed in total for the concerned printer - keep track of that, using the information from the printer for an estimate of ink remaining in the tanks. Subtract the remaining ink in the printer and in inventory from the total starting and purchased volumes, and we know reasonably well how much ink we have consumed. At some point after quite a few square feet have been printed (I recommend several hundred), divide the square footage printed into total net ink consumption and you have a decent measure of ink usage per square foot, combined for printing and maintenance. Since both are essential for producing a print, they don't need to be separated to understand total ink cost per print.What we then do with that information I don't know, unless one is printing as a service - in this case it gives decent insight into that element of the cost structure. For people selling prints, other factors will be far more important than the cost of ink.

That's an interesting point.  After running an ipf 6100 for four years I worked out the cost of paper and ink. Firstly though, using the figures in the print driver which show exactly how much ink was consumed for each print, early on I had determined that the paper cost quite a lot more than the ink.  However looking at all the paper and ink bought over the four years I was surprised to see that in fact I had spent almost exactly the same on both - around £6500 each. That works out by the way at around 65 30-metre rolls of 24" paper.

Jim

[Peter McLennan]

The bags are opaque within the cartridges as well.  Both to protect against exposure to light (UV, etc).

Why?  Do these inks not last for decades when exposed to light?

btw, here's the Wired article.

http://www.wired.com/magazine/2011/04/st_whatsinside_inkjet/

And yes, I did note that these were dye carts, not pigments.

[Moreno Polloni]

Why are carts opaque? 

Probably so you can't see how much of the Epson $3,274.88 per gallon ink is left.