ISO 216 vs U.S. paper

[Christian Rose]

On 2/21/08, Callum Lerwick <seg at haxxed.com> wrote:
>  On Tue, 2008-02-19 at 18:44 +0200, Pekka Pietikainen wrote:
>  > Note that LC_PAPER isn't a standard (except glibc >= 2.2 or so, not
>  > POSIX or anything like that. libpaper even less so, sure.
>  >
>  > Still, it's definately the way to go, why have an extra library when
>  > glibc has everything that needed. Patching libpaper to use LC_PAPER
>  > if /etc/paper.conf doesn't exist (and even trying to get that upstream
>  > to do that with their libpaper) might be useful too, not that anything
>  > in Fedora seems to even use it currently.
>
>
> The problem here is that paper size is *not* a system wide property or a
>  user preference. What really matters is what is physically sitting in
>  the printer tray. It is a *per-printer* property. In fact, a per-tray
>  property. Fancier office printers could very well have letter in one
>  tray, A4 in another, and a third full of envelopes. What about large
>  format printers? A single machine may very well be connected to an
>  office laser with letter, A4 and envelopes, and also be connected to a
>  poster printer with a 36in x 100ft roll of paper in it.
>
>  Anything else is just guessing.

Just because the need for exceptions exists doesn't make sane defaults
less useful. And often, an educated guess may make a very useful
default.

At work we buy and configure a lot of office printers, from small
desktop ones to big copiers, and yes, the big ones always carry more
than one paper size. In fact, all of the big ones carry A3 in at least
one tray in addition to the multiple standard A4 paper trays. Some
printers also mix paper qualities and carry 100 g/m² density archive
paper in some trays, in addition to standard 80 g/m² copier paper. And
so on.

Yes, I agree with you that paper size and quality will always
ultimately be a per-tray setting.  And all of the big copiers that
carry multiple sizes and qualities always need some level of one-time
configuration -- someone has to decide what paper goes where, and
configure the printer and printer drivers accordingly. That
configuration is usually done once by whoever installs the
printer/copier, so that regular users need not care much.

But there's no reason why a generic small printer with only a few
trays or even only one tray would need that amount of configuration to
be usable. An educated guess whould go very far down the lane of
making the printer useful in less annoying minutes.

An "educated guess" in this case means that because "letter" paper
sizes is nowhere to be bought in this country[*], and everything in
this country is using ISO paper sizes (A4 being the most used of
course), making anything but A4 be the default setting if I hook up a
generic printer, and don't specify anything, would make an insanely
stupid default. Any school kid knows that A4 is the standard paper
size in this country -- there's no freaking way computers couldn't do
as well in picking a default.

Luckily, brave people have added this piece of information to
computers, and created things like LC_PAPER. The setting
LC_PAPER=sv_SE, like any school kid in SE, knows that A4 is the
default paper size in SE.

LC_PAPER is for defaults -- it doesn't know what printer you have or
what trays it has, but provides a really educated guess for a usable
default value. Then, of course, CUPS and applications need to use that
as a basis for their defaults in turn, and need a way of specifying a
different configuration if need be. But that's not an argument against
a usable default to begin with.

[*] And hardly anywhere outside of North America, in fact.



Christian