1. Did compose pages as a whole, or in pieces?
Generally as whole pages; looking at the Chronologie
volumes however will show you that the artwork was not always treated like we might expect, so original art was re-drawn over to fit it to an album page, after its use in the Petit Vingtième
, or for some other purpose, which may be why it ended up as you have seen it.
It did vary though - the Unicorn
and Red Rackham
strips were designed to fit the constraints of a daily newspaper publication, and then the frames were re-assembled into book page. The strips were thus composed for the newspaper format, and re-purposed for the book in new layouts.
You can see evidence of this in a subtle change between the black-and-white and colour versions of The Secret of The Unicorn
If you look at the book in the scenes where the Bird Brothers are pursuing Tintin, on page 42 of the book, the bullet which strikes the suit of armour in frame 3, the last frame on the top tier, hits a dinner-gong in frame 4, the first frame on the second tier.
In the newspaper original, the two frames are adjacent, so Hergé aligned the two bullet "whoosh-lines" indicating the path, so that the bullet appears to pass directly from panel to panel. It's a very subtle effect in the newspaper strip, but totally lost when the panels were re-used for the book.
2. How did this process change over the course of his career?
Not greatly - there are full pages of Soviets
available to see in Chronologie
, and the pages from Alph-Art
are in that book. He did seem to go through more thumbnail-rough-pencils-inks type development after the initial albums; the early art clearly has him working out his composition on the page, then inking straight over his pencils, gouache-ing out errors and re-working, probably bcause he had to work at speed - later on, with more time, he perfected the pencil art before inking.
3. What are the dimensions of the original art pieces? Or, to ask another way, in what proportion to the printed artwork did Hergé work?
He seems to have worked on paper just slightly larger than A3 for most of his life (it wanders a bit if you look at the dimensions of individual pages in the Chronologies
, but it remains in that ball park).
There is some discussion of it here