Split Print Job to Color and B&W?

cheros writes "I work in an office which has various printers, and printing documents with a few color diagrams in is actually a pain. Due to the high cost of the color prints the preference is to use B&W, and print the color pages separately (with obviously an finishing stage to collate and merge the two). Is there a print filter that would automatically split the PostScript print job into a feed for two different queues? (and yes, we use B&W drawings where possible ;-)."

Comments

Cool idea, but necessary anymore?

[dschuetz]

To answer the question: I have no idea if such a filter exists, sorry. But it's a cool idea.

On the other hand, don't most "modern" color printers (especially the toner-based ones) print b&w almost as cheaply as regular printers? I seem to recall that some Tek wax printers even came with "free black for life" to encourage use of the printer as the primary output device (you'd short-circuit their moneymaking strategy by making sure that only a few pages in the run contain any color).

The only other thing I can think of is to send the whole document to a B&W printer, then only the color pages to the color printer, but then again, that's probably the way you do it already. :(

If you're working with unix print servers and postscript printers, then I'd think it should be relatively easy to write such a filter. It'd get a bit hairy when you try to do double-sided stuff, as you'd have to track which side you were currently processing and send both sides (where one is color) to the color printer. But it should be reasonable to do, I'd think...

input filter:
- receive pages
- scan page (or pair of pages on a single sheet)
- is color there?
? yes, write this postscript snippet to file A
? no, write the snippet ode to file B
- when done:
- lpr -Pcolor a
- lpr -Pgreyscale b
- lprm self

Or somesuch. Of course, I haven't screwed around with lpd print filters in, oh, 5+ years, so I may be way off base.

My advice: Find a unix geek (preferably a PS-aware perl programmer) and promise them a six-pack of really nice beer if they can solve the problem for you. :) [of course, if you're using a windows print server, you'd better make it a case.]

good luck!

Doesn't the printer already do that?

[CrisTUFR]

I have a Xerox XPrint 4920 Plus colour laser printer here, and I see where you're coming from with this question. The thing I'm wondering is why the printer you have doesn't do the job-splitting for you... Colour toners for this bad-boy cost about $350 CDN each (C,M,Y) and the black toner is only about 60-80 bucks CDN. The difference in price (and speed, as B&W prints come out at 12ppm vs. 3ppm for colour) means that I can use this printer for both my colour and black&white needs. Obviously, B&W is higher quantity, and when printing mixed documents, it seems stupid to print through the CMYK process... Well, here's where the printer gets smart -- it doesn't print the pure B&W pictures through the CMYK process. It appears that the printer figures out that it only needs the black toner and just sends the page there. I don't see why you would need to split the actual printers if the printer *should* be doing the splitting for you (and keeping costs down adequately). I guess the particular printer you're using must have a very expensive black toner... NOTE: The XPrint 4920 Plus was introduced in '95 and is by no means a 'new' printer.

Re:Doesn't the printer already do that?

[fooguy]

Chances are yes - the printer already does that.

If your color printer is CMYK, then you're already saving as much money as you could. Granted, you're shortening the life of the fuser by running more pages through it, but in the end the cost is so minimal that one person printing wedding shower invitations will blow your savings to hell.

Now, if your color printer is RGB, then you are printing RGB black and it is costing you more. My suggestion (if you really want to save money in the long run) is to get a CMYK color printer to do double duty. You'll only be using one printer to do all your printing, and as the parent post said the black toner is a lot cheaper than the color.

Note: to my knowledge, the HP color printers are all RGB. Coming from a print environment, this does really suck.

Re:Doing the filtering

[dschuetz]

one trick that could work would be to add some functions in the postscript header. Basically, overload all color operators so that if they are called, they flag the current page (or better they check if the color or image they are passed is really color). If the flag is present ignore the next showpage operator and flush the graphic state.

Oooh, I like this one. Combine this with what I'd described earlier -- have the input filter add this to the heder, with "ignore==color" and send to the B&W printer, then again with "ignore==b&w" and send to the color printer.

Again, though, I think you're going to depend on having a geeky-geek there to write it for you (and more importantly, fix it when it runs across really weird data that doesn't quite fit right...)

Commercial solution ... but proves it exists.

[ip_vjl]

there's a page on richoh's site dealing with their Velocity product that seems to do this.

Velocity Workflow software features a modular design that enables you to manage multiple print engines, balance print jobs or split print jobs between Aficio color and/or black and white print engines.

This seems to be for those using their systems, but seems to offer evidence that the idea at least exists out there. Years back when I worked at Xerox, I thought I remembered something in development to balance a job between the B&W DocuTech and a color printer ... but don't know if it ever became a product, got worked into existing stuff, or became obsolete due to reduced printing costs on the color devices.

--

BTW - searching google for split print color b&w popped this up first result.

Think I did this...

[Bazman]

..but I cant find the code. How did it work? Well, maybe like this...

Write some postscript that redefines all the colour-setting commands and the colour bitmap commands. The redefined commands set a variable to say this page is colour.

Redefine 'showpage' to only do a real 'showpage' if the 'page-is-colour' variable is set. Clear the variable.

Now rerun, but reverse the logic to do 'showpage' on the mono pages. You can pass the sense of the logic to ghostscript on the command line.

Of course this wont tell you if there is a grey-scale bitmap in a colour image command. You could always redefine the image command to check that all the pixels have the same r,g,b colours....

I'll try and dig the code out.

Baz