How to write proportional notation: space = time

[Laurentpigeolet]

Hi,

I installed "spacing notes" and "proportional spacing" plugins.

I would like to fix one dimension of some choosen bars to get a perfect proportional notation, with a perfect relation between space and duration;
For example: 1 bar in 4/4 = 4 cm, so a quarter note = 1 cm, an half = 2 cm, a.s.o, for all the bars I want. How can I do that? How to avoid automatic flexibily? How to avoid small bars when there is a few notes and big ones when there are a lot of notes? In most of cases, flexibility is good, but in others situations, almost in contemporary music, we need perfect proportional notation. I would like to conserve the same dimension for all the bars I choose. It's important fro me, for example when I write a logarithmic accelerando: I would like to see the spaces between notes diminishing gradually without visual spacing breaks, and conserve in the others staffs half notes perfectly equals (visualy), and not like on this score (see attachement). I know I can put the first notes of the bars on the dashed barlines, but it's not enough. In this sketch example, the 3th bar is too much small and the half notes are not equal. How to make it equal to the 4th bar without having to move every note individually?

Many thanks,

Laurent

[dircules]

Here is how I once solved that issue for me: Create an extra staff and fill it completely with notes of the smallest used value, e. g. 16 16th. Each time Sibelius adjusts space, mark that staff and click (my translation from Sibelius' German version) Appearance > Reset Note Spacing. To print out your score, make the staff invisible (and hide empty staves), or work with parts; and prevent it from being played back.