There is an oft-repeated claim that Art should Stand Alone, a claim hinted at in some recent comments here but not stated outright (I think).
It's worth unpacking this a little, to try to figure out what it actually means. On the face of it, the idea is both very modern and absurd. Modern, because until recent times no Art even attempted to stand alone, it was always shown (if at all) in context. It hung in the home, it stood in the palace. Even today, paintings from before the modern era invariably sport absurdly ornate frames, sculptures stand on pedestals, and so on. Only the most modern of art, in the most modern of museums, is shown without being first encrusted with decorations.
Even the most austere white cube filled with the most austere modernist black and white photographs admits frames, glass, mats, and lighting.
The standard monograph, that sarcophagus for photos, with one picture per page, white paper, large margins, has a cover, the paper has weight and texture. To suppose that the photographs of The Americans or American Photographs stand alone in any literal sense is absurd. More important even than the heavy, luxurious paper, the massy weight of the volume, the thudding weight of The Essay, the photographs sit with other pictures.
In these two books, the ur-monographs, the sequences are linear, unsubtle. Anyone can see them.
In contrast to this, in these modern and degenerate times, we see the so-called design forward book. This is usually a rotten collection of rotten photographs, lumped into a book with pointless gatefold pages and equally pointless die-cut bits and pieces, sometimes with an outré binding to further distract from the weakness of the work.
What I think we really mean by "the art should stand alone" is that we want surrounding design elements to avoid distracting us. We want the Art, whatever it is, to take center stage.
When we read through The Americans we see the photographs first and foremost. The other elements of the tomb are nearly invisible. They rise to the level of conscious note only to people like me, to book nerds. This does not mean that they're not perceived. A book with thick, heavy, toothy paper is going to feel quite different from a book with thin, glossy paper like a magazine. To someone who does not even note the paper, the first book will feel expensive, luxurious, compared with the second one.
We can expand this slightly, and assert that in a book design the elements should function in a hierarchy. You should notice things in a specific order, the photographs first, then the captions, then the delicate horizontal rule that separates the two, and then the thick but glossy paper, and lastly (if ever) the tastefully positioned page numbers.
Indeed, you could remark that it doesn't matter what you do - the design elements will find themselves in a heirarchy. That is, people will notice them, in order, until they've either spotted them all or run out of interest. If you as the book designer are not in control of that order-of-perception then you're going to have trouble. If you stupidly chose a huge flashy font and red ink for the page numbers, well, the photos are likely to get short shrift, right?
In some cases, of course, you want at all costs to avoid the photographs getting long shrift, which is where all the gatefolds and whatnot come in.
Conversely, if your page numbers are important (perhaps the index is a common access point to the book) and they are damn near invisible (I own a cookbook like this) then you're created a book that doesn't work. It's broken.
All of this is just ancillary food for thought, though. The point is that there are and always will be design elements in a publication, and while they may pass unnoticed, they are nevertheless part of the work, and will tend -- though unnoticed -- to influence the way people use and react to the publication.
Mostly what people use is something I am going to dub static design. That is, elements of the pages are the same from one page to the next. Page numbers are always in the same spot. First pages of chapters all look the same. Body text always looks the same. Graphical elements are repeated on every page, the same way.
The idea, here, is obviously to provide a sort of anchor, a constant presence that will make the work feel both finished and unified.
A good design sets the tone of a book. It makes it feel playful, serious, elegant, punk, luxurious, or whatever. You set your design down, and then you adhere to it, and the overall tone of the book flows throughout the book. It does not merely feel playful, it feels consistently, purposefully, playful. It is a playful book, from page 1 all the way through to the end, to page 217.
Finally, now, we work around to the point of this piece.
Nothing else in a publication holds still in the way that design does. The words move forward from one sentence to the next in all but the silliest of publications. The pictures are different from this page to the next, ditto. The content progresses, but somehow we oppose the notion that the design should, except in the most unsubtle of ways.
One might switch from heavy paper to light paper, or from one background color to another, to signal a change in content, a new chapter. I see this sort of thing from time to time.
What I do not see except in my own books is subtle progression, or continuous progression. While design should, ideally, be unobtrusive, and while it is certainly a useful tool to make the book hang together, there is no particular reason the design cannot subtly alter from page to page.
A piano concerto does not contain a single mood. It may change from playful to serious, and it does not do so in a single sudden stroke. A serious theme is introduced, at first seeming only a variation of the playful theme. It grows, becomes more serious, and, after a time comes to dominate the music for a period of time. At the same time, the underlying harmony moves, the key signature modulates. The change to minor key may well go unnoticed by all the non-musicians, but they will certainly feel the gathering storm.
What this means in practice is that the elegant horizontal rule that separates the photograph from the caption might, for example, become lighter from one page to the next, and then fade out entirely at the point that the captions change from Times to Comic Sans and the pictures move from black and white landscapes through muted color before landing on candy-colored saturation and a circus theme.
By holding some elements steady and letting others flow, you can adjust the sense of unity in relation to the sense of flow and progress.
Only a few people, like say me, might notice the changes, but many will (I believe) feel the change in tone, the change in idea. Or, depending on how heavy-handed you are, they will explicitly notice the design changes as well!
Here is my best so-far-realized example, a book available for purchase on Blurb: Bellingham Summer. I would of course, not object if you bought a copy but that is not my point here. Click the Preview button and examine the preview. You can see the whole book there. Enbiggen it to full-screen if you can.
Notice the way the background changes. The flock of little pictures "grows" out across the pages, and then the content begins, the little pictures fade into the background. When there's no picture in front of them they re-assert themselves a little. Then they begin to vanish from the bottom up, imperceptibly, or nearly so. Finally, the last couple blink out and are replaced by a swirl of leaves that blows off the book.
Now, these are not traditional design elements (horizontal and vertical rules, ornaments, chapter heads, that kind of thing.) I've invented background material that looks distinctly un-booklike, because I had in mind something else. I suppose you could argue that these are just more content, but they're certainly a different category of thing. I have another sample in the works which uses a progressive approach to more traditional design elements in order to support the book's natural progression.
Anyways. Most tools for book design encourage static design approaches. The model is built around page templates, which hold all the material which is the same page-to-page, and content which is different page-to-page.
I think there is maybe room for some middle ground here. There is room for supporting material, for background material, which changes and flows to support the change and flow of the book itself. I'm doing my best to explore that!