Paper Screen Character 
& Grit sizes
# Diamond grit particle size 
a micron 1μ = 1/1000000 metre or 1/1000 mm

1000 grit  particle size 15μ
 400 grit  particle size 75μ
 
sharpening and toolcare link  

#  Characters
10 cm = 118 pixels @ 90 dpi
A 12pt emsquare is 15px

The following notes relate to the DTP point (pt)
pts to inches link

 1 inch is 72 pts
 1 pt = 1/72 in = 0.0138 in  = 0.3527 mm

a character with a height of 12 pts is a pica, there are 6 to the inch
    so pica should print 6 lines to the inch by default
But the width is a different kettle of fish:
    characters are designed to fit an em square.
    the font is scaled so that its em square has a side length
    of that particular length in points
It does not work out in practice
    using a fixed pitch font - courier and the string 012346789AB
    at 12pt the string is 1.2 ins
       10 pt              1.0 ins
     
So what font size is 100 characters per inch?
    in = 72pts
    in/100 = 0.72pts
However in practice in ArtWorks using font size 1pt
    0123456789ABC is 1/10in long so:  100 chars per inch is 1 pt
    Reference the "one pound" printed around the rim of a one pound coin

# Screen monitor sizes
 ACER AL2416

  diagonal      24"
  horizontal    20 3/8"
  vertical      12 3/4"
  horiz pixels  1920
  vert  pixels  1200
  works out as 94 dots per inch horizontal
               94 dots per inch vertical

 curious cos istr risc os uses 90 dpi which would give screen dimensions
 of:-
   21.33" x 13.33"
   looks as if I need to check print size versus screen size also

# Paper Sizes  ISO
The ISO 216 standard is based on an aspect ratio of the square root of two,
like the side of a square and its diagonal. 1:1.4142
This idea was originally proposed by the German scientist Georg Christoph Lichtenberg in 1786.

 A0     size one square metre
        841mm x 1189mm
 A4     210mm x  297mm           approx 8.27" by 11.7"
        595px x  842px           (72dpi used by postscript)


Paper size American
 American letter size 8.5" by 11"
        (90 dpi = 3.5433 dpmm)
        744pix x 1052pix
        (650x1000) to allow print margins

Flash cards
 the spanish flash cards are 1/128" thick

A4 - Suzano Report Laser & Inkjet 80gsm

vacuum pack  - 500 sheets - 4.88 cm
loose          500 sheets - 5.16 cm
average          1 sheet  - 1 mm

Passport photos should be 35mm x 45mm or 413 x 531 pixels
 the face length should be in the range 29mm : 34mm or  350:400 pix

# - I want a 2 fold A4 flyer
   Complete your document, pages 1 - 6 in that order.
   Cut page 1 to clipboar
   Page 2 moves up to page 1
   Paste page 1 to the now vacant page 6.
   Check that your page breaks haven't been altered - adjust if necessary
   Print . . .
   If you've only got six pages, once the document is complete, the fact
   that you've lost a page link is of no consequence.

© JR 2013