Digital BW, The Print

I recently downloaded a 21-step wedge from some pointer is this
group.  The file was called '21stepNew.jpg'.

I think there's a slight error, of scaling, in the file.  In
Photoshop Image Size, the size is listed as 3 x 9.6", at
300 pixels/inch.

But the 7.2 lp/mm resolution target has 2 pixels per line pair.
This means the resolution SHOULD be 144 pixels/cm to make the
resolution target be printed at correct scale.  Which is somewhat
different than 300 pixels/inch.  This scaling error applies
to the other resolution patterns as well.

Of course, the simple fix is to change the rez to 144 pixels/cm,
(without resampling, of course).  The size then becomes about
2.4 x 7.9".

John