Hi Frank,

> but sticking with it for a moment: golden ratio between what? (i know
> it is also only meant as an example, but what are the ingredients?)

place top of float area so that the ratio to the height of the page is
like the golden ratio 
 
+ a   ttt  ttt
|     ttt  ttt
|          ttt
| b AAAAA  ttt
|   AAAAA  ttt
|   AAAAA  ttt
|          ttt
|     ttt  ttt
|     ttt  ttt
+ c   ttt  ttt

bc/ac = golden ratio; e.g. if the height of page has 42\baselineskip
then b would start after line 16 (if I calculated correctly ;-)

>  > No, not on a per page basis. More a spec for defining float areas,
top
>  > and bottom are self-explaining but some absolute measure allows for
>  > visually pleasing placement of 'middle' areas (and combined with a
>  > 'vsize' option you can get a consistent layout), e.g.,
> 
> ok, but can you be a bit more specific as to what the pictures are
supposed to
> tell? I'm not at all sure why there is sometimes empty space after or
before the float
> rule (which perhaps is just meant to indicate the area for placing
floats (?)=
> and sometimes not)

the rule in the picture should have indicated the area, the empty space
means that for a consistent design -- if the concrete application is
suitable for that -- you reserve the same vertical amount and place the
pictures top aligned with respect to the area. Of course this will only
work in an application where there aren't very tall pictures ... but
then a fixed middle area wouldn't be the right design.
 
> so can you perhaps give some explicit pseudo specification?
> 
> \DeclareFloatArea
>   {  position = m  % (or t or b)
>     ,column   = 1  % 2 3 4 ...
>     ,span     = 1  % 2 3 ...
>    ...             % your spec
>   }

\DeclareFloatArea 
  {  position = m  % (or t or b)
    ,column   = 1  % 2 3 4 ...
    ,span     = 1  % 2 3 ...
    ,vsize    = 6\baselineskip            % vsize of area
    ,pos      = absolute(16\baselineskip) % vertical starting position  
  } 

> precise enough to make your picture example page come to life :-)

maybe a global definition which can be overridden is more useful, e.g.,
 
\DeclareFloatAreaMiddle
  {  columns  = all                       % {1-3}, {1,2}
    ,vsize    = 6\baselineskip            % vsize of area
    ,pos      = absolute(16\baselineskip) % vertical starting position  
  } 

then in case of a float like on my page 117 we define

\DeclareFloatAreaSpan
  { ,columns  = {1, 2} % applies to columns 1 and 2; other possibilities
'{1-3}, all'
    ,span     = {1, 2} % span applies to columns 1 and 2; '{1-3}, all'
  } 
 
> =========================================
> 
>  > > But what I'm after is this:
>  > >
>  > >  - assuming you have the possibility of specifying one (or more?)
middle 
>  > >  areas for floats by which I mean an area to receieve float(s)
where
>  > >  above and below there is still text

this should be covered by my above definition (text above
16\baselineskip, float area 6\baselineskip, text after
42-(16+6)\baselineskip).

>  > <rulers>, <colour specs, including transparency>,
> 
> aren't those more kind of decorations on the area? so in other words
> irrelevant for placement (other than the decorative elements might
need space)
> or do i miss something.

yes, that's true but where do you define global definitions for the
visual appearance? And one should always have the possibility to
override some specs, e.g. in a special case one might not want top
rules.

\DeclareFloatArea 
\DeclareFloatArea<Middle|Span|...> % if necessary
\DeclareFloatAreaAppearance % ?

> can you explain what you mean by "including transparency"?

You should be able to define background colour|pictures, rules (top,
bottom, box, coloured), transparency for background colour|pictures and
maybe even a gradient colour. Plus a command to override the global
definition in a special case.
 
>     * The ratio of t1 to t2 is fixed by the design and a float AAA can
be
>       placed into the middle position if neither t1 nor t2 become too
>       small. (Downside of this kind of layout might be that the
positioning of
>       the floats drastically varies from page to page.)
> 
>     * The end position of t1 is fixed (vertically) so that a middle
float
>       always starts on the same point on a page. Further restriction
then that
>       t2 is not getting smaller as a certain value.
> 
>     * The starting starting position of t2 is fixed so that the bottom
of the
>       middle floats always appear on the same vertical position on the
page,
>       again with some further restrictions to the size of t1 this
time.

I thought this was what I'd proposed.
 
>     * An obvious extension to the above could be that there are a list
of
>       vertical starting points to choose from and some
>       mechanism/logic to select one of them
> 
>     * ...other ideas...

sorry if my explanations are too cryptic.

Ulrich