>>> However, it's worth noting that, unlike many lasers and imagesetters,
>>> the high resolutions quoted for inkjets are nominal; 2400 dpi does not
>>> imply a smallest possible dot of 1/2400 inch.
>
>>What about digital printing presses that are advertised as 2400 x 2400
>>dpi?
>>These are the big machines, made by Xerox, Oce, Indigo, and a few others.
>
> These million dollar machines should be true to their quoted
> resolution. They aren't inkjet. But they can be expected to use
> halftones. One key reason for this is that many paper/ink conbinations
> have a minimum effective dot size. They may not be suitable for your
> highly specialised application. Indeed, it's hard to imagine that
> ordinary paper can deliver at all. Printing on photographic paper with
> an imagesetter may deliver what you need.
Thanks. This is very true. I am giving up on printers. You are right,
imagesetters are expensive, and they are hard to own. When I use an
imagesetter service, the cost per sheet is high, and there is the hustle of
sending files and receiving the output, and the cost of mailing. Maybe I
can find a 'small' 'easy to own' 'inexpensive' imagesetter, yet maybe that
is impossible. I always outputted to film. I wonder if I can output on
white paper.
> Printing on photographic paper with
>an imagesetter may deliver what you need.
Caveat: I'm not an expert on this sort of thing, and you probably need
to find one before investing the serious money needed.
----------------------------------------
Aandi Inston
Please support usenet! Post replies and follow-ups, don't e-mail them.
I'm not sure you are understanding the printing process for inkjet
printers fully.
There are several differing inkjet printing technologies used. For
instance, Canon and Eposn do not use the same methodologies/
The Canon printer uses a thermal head which literally heats the ink at
the very tip of the head and when it boils that change of state causes
the gaseous state to provide pressure to expel a droplet of ink to the
paper. This method doesn't allow for much variation in dot size. As a
result, Canon heads (depending upon the model) have three sets of
nozzles. The very small dots you speak of are not produced by the same
ink nozzle as the larger ones are. A larger dot is used to create
larger denser areas of color.
The Epson head, as one example, is called a piezo mechanism. Unlike the
Canon, it is a cool (as in temperature) method that involves the piezo
actuator vibrating and that frequency causes the fractionation of the
liquid ink which is then expelled through the nozzle in the head. In
the case of Epson printers each nozzle is used for between 3 and 7 drop
sizes, depending upon the model specs. The nozzle is large enough to
allow even the largest dot size to get through as well as much smaller
ones.
Art
If you are interested in issues surrounding e-waste,
I invite you to enter the discussion at my blog:
Talal Itani wrote:
>>> Your explanation brings another question:
>>> 'why do some printers require a dedicated RIP box?'
>> Well, understand that the "rasterizer" is always a separate computer
>> dedicated to the task of rasterizing. Some printers depend on your host
>> Windows/Macintosh computer to do the raster processing, others install
>> the RIP computer inside the same case with the laser engine, and others
>> place the RIP computer outside in its own case.
>>
>> But in every case, there's a separate RIP. In two of the three cases
>> above, it's a dedicated RIP.
>>
>> In high end situations, you want to separate the RIP from the engine.
>> In all cases the output of the RIP is a raster pattern that the engine
>> can use, but inside the RIP can have many different features. To
>> facilitate giving the customer what he wants, it's far easier to let him
>> pick and choose the RIP features separate from the engine features.
>
>
> ok. That made sense to me. Inkjet printers, like the Canon I have, have a
> resolution of 4800 x 2400 dpi. When I use a loupe, I can see the very very
> tiny dots. The dots are tiny when the colors are light. When the colors
> are dark, the high-resolution is not maintained. This is because the rip of
> the printer is very powerful, and the rip cannot address every single dot
> individually. I have a project that requires high-resolution, and being
> able to address every single dot individually. I learned that a separate
> RIP can be purchased for this task. Do you know more about this?
>
> Thanks.
>
>
OK, I stand corrected. I wasn't sure, which is why I prefaced my remark with 'AFAIK'. Thanks for the enlightenment.
--
Cheers,
cmyk
"Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote in message news:elmop-54D805.23465404072008@nntp9.usenetserver.com...
> In article <6d7l8cF19mg0U1@mid.individual.net>,
> "cmyk" <cmyk@invalid.invalid> wrote:
>
>> AFAIK, Laser printers, however, only quote the actual hardware resolution as
>> they're unable to vary the amount of toner at a given
>> location - it's an all-or-nothing affair.
>
> No, not at all. They can modulate the intensity of the laser at a
> certain dot, and many high end color lasers can do 600x600x8--that is,
> 600 dots per inch at 8 bits per spot, for 256 shades per spot.
>
[A complimentary Cc of this posting was sent to
Talal Itani
<titani@verizon.net>], who wrote in article <Bvwbk.794$al3.102@trnddc06>:
> ok. That made sense to me. Inkjet printers, like the Canon I have, have a
> resolution of 4800 x 2400 dpi. When I use a loupe, I can see the very very
> tiny dots. The dots are tiny when the colors are light. When the colors
> are dark, the high-resolution is not maintained. This is because the rip of
> the printer is very powerful, and the rip cannot address every single dot
> individually. I have a project that requires high-resolution, and being
> able to address every single dot individually. I learned that a separate
> RIP can be purchased for this task. Do you know more about this?
I can't give you the exact answer (and the answers you got here do at
least look "very reasonable"), however, I want to point you to either
some code which DOES work directly with "dots" (as opposed to
"pixels") of a printer, or the people who wrote this point.
In particular look at the last clause of 6.1.8, (8):
Applications with special requirements can now access the raw ink
channels directly. This facility was used to create a mechanism to
more accurately tune printer inks.
Looking around this page (p.41), one can guess that this code may be
accessing ink drops more or less individually. I would guess that
using (some modification of) this code, one could position drops with
the granularity restricted by hardware only. (Moreover, looking at
the code, you might be able to find out what are EXACTLY the
limitations of the hardware.)
[Keep in mind that other answers in this thread discuss more or less
limitations of HARDWARE + THE PRINT DRIVER. The code above may
have fewer limitation.]
[Disclaimer: I myself did not look at the code in question, only
looked through the user docs. Better try to contact developers
first...]
Re: Why a Rasterizer ? 
Linear Mode
