Digital BW, The Print

On 20 Sep 2004 at 13:07, Ernst Dinkla wrote:

> A  sizes serve a purpose but don't add too much value to them. 
> Lots of other sized papers available here and even in Japan that 
> is more metric than Europe.  While it is nice that an A2 can be 
> cut in half to get two A3's and an A3 can be cut in half to get 
> two A4's there's something odd going on. How many users actually 
> do that ?  The paper distribution chain can use that nice aspect 
> only for unprinted stock that goes to the customer unprinted. But 
> the printer needs a sheet that is larger than an A size for grip 
> on the press, cutting it straight before it gets on the press, 
> etc. That larger sheet can't be halved before the printrun on 
> another smaller press because the margin for grip has to stay as 
> wide as it was on the double sheet. All kinds of paper sizes that 

There is a standard for raw paper stock as well, the A series sizes are for finished 
(trimmed) paper sizes, there is a RA standard for raw (untrimmed) sizes.  An A4 
sheet is 210 x 297mm A3 is 297 x 420.  RA4 is 215 x 310 RA3 is 305x430.  This 
gives you 5-10mm for trimming, considering that presses most likely across the 
longer dimension, this gives adequate room.  There is also the larger SRA sizes, but 
unless you work in the press industry, it's unlikely that you would see those.  Most 
likely the printing company would buy rolls of SRA width stock, then trim that to RA 
size before feeding the press, and then the bindery would receive that, and trim as 
needed.

The last time I saw printing press output, it was at a bindery, 4 finished letter sized 
pages, printed duplex to give 8 actual book pages, on one sheet of paper, this was 
then folded by a big machine, and trimmed using a machine that would stamp out 
the pages on three sides, and stitch or staple the fourth.  There is a set of rules as to 
the order of the pages on the paper, some are upside down, hint, they are not in 
numerical order!

> are a bit larger than A sizes available at the printer supplier 
> and they can't be halved. I doubt that there's less waist in 
> Europe with A sizes than there's in the US with a more sloppy 
> standard. Small sheets usually are made of a lower weight paper 
> than larger sheets as they are used for different tasks. When it 
> is possible to cut a sheet in halves on its thickness the picture 
> changes but that's not happening in my time :-)

Often though thickness is dependant on aplication, for example a sheet of onion 
skin paper, letter paper,  and photographic paper will all have different thicknesses, 
even if they are the same physical dimensions.  However the metric grams per 
square metre actually makes more sense then pounds, which is based on the weight 
of an arbitrary number of sheets of an arbitrary size.  

Now, in the darkroom, metric sizes make even more sense, each time you increase 
one size, you need one stop more exposure, due to light loss,  each time you 
decrease one size, you need one stop less exposure.  I used to know the formula for 
inch sizes, and man was it UGLY.   

> The standard is a good thing for equipment that has to work with 
> it and a worldwide standard will even be better. But I'm printing 
> 56x76 cm serigraphs right now on halved Arches Velin sheets of 
> 80x120 cm on a 100x140 cm Thieme silkscreen machine. Only the 
> last has some relation to B size (same ratio as A size but 1.4 
> larger in M2). Metrification of the whole world (including paper 
> weight) is far more important than paper size standarisation.
> 

The only real holdout left is the United States, and you can get metric sized paper 
there.  What is also an issue though, is digital sensor sizes, there should be 
standards there as well, at this point, it would make sense to have sensors with the 
same aspect ratio as metric paper sizes, but I think 35mm aspect ratio will probably 
end up more likely.   What will really help, in Canada and the US is the schools, if 
they use metric sized paper when children are first learning, then they will be 
familiar with those sizes, when they are older, and will ask for metric sizes, because 
they are used  to them.  This will be much easier in Canada, then in the US, 
because the inch sizes are not mandated over the metric ones by law.

Paper isn't the only holdout though, couriers are the other one, they still weigh in 
pounds, simply because they haven't figured out that if the drop is 100g you can 
make more money on a 400g shipment, then if the drop is 1lb (454g).

W