I think we all understand that the problem you're addressing is
a serious one. Inkscape will render older images based on 90ppi
at a smaller size when it changes its definition for pixels per unit. 

Since there had been discussion of absolute size in the thread,
I thought that the conversions might be of interest to those who
might have a project that requires absolute sizing, even though it is
of no help to you. <snif>

And thanks for the heads up about 2.54cm/inch.  I've been using
some sewing books which make recommendations of rounding to the
10th rather than 100th perhaps because they were using pencil & paper,
and it worked well enough for them personally.  This is ultimately
garbage advice, so thanks for pointing that out.

Question: Are there differences between Inkscape and other tools
regarding pixels per inch?

- Susan

Date: Wed, 12 Jan 2011 08:57:09 -0500
From: Shawn H Corey <>
Subject: Re: [Inkscape-user] Inkscape Accuracy

Conversion is not the problem.  The problem is that the number of pixels
per inch keeps changing.  It's currently 90, schedule to change to 96,
and may change again.  That means that old SVGs will become 7% smaller
when the new scale is implemented.  And that's *all* the old ones since
Inkscape stores their measurements as pixels.

BTW, it's 2.54 cm per inch.  :)

Just my 0.00000002 million dollars worth,