On Dec 25, 2018, Paul Schlyter wrote
(in et):

On Mon, 24 Dec 2018 22:04:24 -0600,
wrote:
If the numerator is always 20, what does this 20 mean? Is 20/20 in
some way different from, say, 25/25 or.30/30?

As I understand it, you should be able to see at 20 feet as the average
person would see at 20 feet. (An average person with good eyesight of
course.)

If you are shown to have a 20/30 in your right eye it means that you see at
20 feet is like that average person would see at 30. In other words,
your eyesight is not that great.

But what's the point of always having 20 as the numerator? Why not
instead perform the division and say 0.67 instead of 20/30? Or, if
you prefer common fractions, 2\3? After all 2/3 is equal to 20/30.

I haven’t a clue. All I can say is that maybe your local eye doctor might
have an answer. The only thing I can think of is that like any other part of
human life eye doctors stick with some traditions. Nearly every organization
has traditions that are slow to change. As a former Navy person I ran into
lots of old traditions while in. Many did not really make any sense, now.
Maybe they did way back when. As a long time printer we had lots of
traditions on how we measured things, and even in the last ten years many of
those have slowly fallen to the wayside with the spread of digital printing.
We used to have many terms that were in use daily by printers back in 1969
when I first got into the business. When I reentered it about 32 years ago
most were still in daily use. But by the time I was retired a couple of years
ago most new printers had never heard of them even if they had been working
as printers for 10 years or so. The guy that trained me on the big web
presses was always mentioning things that we never dealt with anymore. And of
course when I started as a printer I started on one tower flat bed/flat sheet
presses before much later moving on to web multi-tower presses, again, a very
different kind of printing.

Printing used to be as they used to say: more art than science, same goes for
making eyeglasses. But these days not only are presses being replaced by
digital (laser) printers so are set up and pre-press, most of it is now done
by computers, as is mixing of inks (if you are still using a press that
actually using printers ink instead of pre-mixed cartridges from the
manufacture.)

Kerning, that used to be one of the most important parts of printing pages of
print, and one source of many traditions of how printers measure and move
things. Now nearly all of that is dealt with automatically by the software
long before the image ever leaves the set up computers. This was something
that I seldom had to deal with as I was an offset printer, not a linotype
printer. I have had some conversations with lino printers that have left both
of us scratching our heads even though the presses we both used are (almost)
identical, only the method is placing ink on paper is (vastly) different.
Both types of printing have very different current styles of training. Lino
is even further along towards being obsolete than off-set printing. These
days both types are becoming strictly boutique print shop use. Boutique Print
Shop, three words I never thought I would ever use in a sentence.

It used to be that a printer had to worry about things like what was the temp
and humidity at the time you were printing, and just for fun add in just how
old is that paper you are printing on. Paper that is less then six months old
prints very differently than a roll that is six years old and what kind of
paper, how thick, coated or uncoated, AND how had it been stored during that
time.

Most of the time nobody could tell you this kind of stuff, so you had to
learn by doing and by listening to older printers. This was one reason most
old printers did not really like training people who had gone through a tech
school, they had a lot of book training but very little practical training.
Now most of what we trained for is built into the software and hardware, or
completely ignored since the folks that build them expect the users to
actually use high quality paper, ink and not run them for 24 hours straight
or longer and never, ever cut corners. Things like how much, or little
fountain solution to use aren’t even a part of laser printed jobs. Or that
sometimes you need to add a little alcohol to that solution to fix a toning
problem that just won’t go away no matter what the makers of the machine
say.

The guy that trained me on my last press just retired, the press he had used
for most of his career was almost identical to the one he trained me on, but
the type of printing he did before coming to our shop was very different,
instead of one roll of paper going through the entire press, getting
different inks printed by anywhere from four to ten different printing
towers, he started off printing the old multi layered, multi-colored
forms.What we used to call business forms.

So his press that he learned on had up to six rolls of (basically) tissue
paper being fed into different towers to be printed, collated into a single
form, then it would be cut, glued into whatever form the customer needed.
Collectively these were known as “business forms,” they came in hundreds
of weird and wonderful forms, colors and styles. Having heard the tales that
I was told by my trainer, I am glad I missed that particular form of torture.
His favorite tale dealt with splicing tissue paper back together ten or
twelve feet in the air standing on top of the press or on a ladder using one
hand, the other was to prevent him from falling into the press.

Now years ago I had actually been to his former employer, I saw the presses
he worked on, in function they operated exactly as the one he trained me on,
but the reality was just as awful as he described, far worse really. Rolls of
paper being fed into the press at each tower, paper running above the press
from each tower before diving back into it to be collated and folded by the
bindery unit, I would have believed him if he said he had to do the splicing
while hanging by his toes doing a Tarzan scream. I was only there to pick up
some forms for my then employer, thank Bes. Too bad the family that owned the
company sold it, only to have it closed a year later. But I got a great
trainer out of it and a good friend.

Sorry about all that, but it is late at night and I am bored at the moment
and I guess I have the holiday blues. Why am I suddenly reminded of the old
detective from The Streets of San Francisco? I am not that bad, really.

--
Harry F. Leopold

The Prints of Darkness (remove gene to email)

"The line separating painfully bad analogies from weirdly good ones is as
thin as a soup made from the shadow of a chicken that was starved to death."
- Alydar2