[Therion] Creating PDF/A map files

[Tarquin Wilton-Jones]

> we need tranparency (I think)

Render your survey to SVG, and you will very quickly see that yes, you
need transparency, wherever you get a lot of overlaps. The only other
option would be for Therion to implement its own opacity engine and
output a computed rendering, and I doubt anyone here wants to implement
that.

> We can gzip the files after creation but a
> foo.PDF.gz is a lot less handy than a foo.PDF with internal
> compression.

And Windows users would not know what to do with it.

Does it take much space to bundle the fonts? Those can be extremely
large in some cases (though I guess that part is simplified by Therion
using just one font).

If those are bundled, isn't it pretty much self contained?

I personally see no need to remove compression. It's not like a PDF
viewer is going to somehow lose support for it in future. Browsers have
not dropped support for deflate or gzip. If anything, viewers (for as
long as PDF viewers exist) will gain support for things like that over
time, rather than losing it.