What is the smallest paper dimension that can be used in (La)TeX?

I want to know what is the smallest paper dimension (in big point) that can be used in (La)TeX?

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The smallest unit it TeX is `1sp` (scaled point, 65536 sp = 1 pt). The `preview` package sets its default margin to 0.50001bp (used on all four sites) to ensure that the final size is never lower than 1bp. Its manual states that this is because lower sizes can cause issues with Ghostscript. I therefore wouldn't go below this value either if you plan to use DVI output and convert it using Ghostscript later. –  Martin Scharrer Jul 10 '11 at 12:20
@xport the +1 comment should be included only if you have a constructive comment, not just to make sure you print your name 18341983 times through every post. Just upvote the comment, unless you have something useful to add. –  Vivi Jul 11 '11 at 3:10
@Vivi: Where does 18341983 come from? –  xport Jul 11 '11 at 3:18
@xport : that's a perfect valid point. It's good we are getting to the crux of the matter now. –  Vivi Jul 13 '11 at 9:51
Surely the important "big" number is 2147483647 (the largest integer TeX can handle). That many `sp` is about 37 feet across by my calculation... –  Seamus Jul 16 '11 at 11:14

`pt` is a unit defined by TeX, also called TeX point (1in =72.27pt). The one for PostScript is `bp`, also called big point (1in=72bp), the reason why it should be at least `1bp x 1bp`

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The smallest unit it TeX is 1sp (scaled point, 65536 sp = 1 pt). The preview package sets its default margin to 0.50001bp (used on all four sites) to ensure that the final size is never lower than 1bp. Its manual states that this is because lower sizes can cause issues with Ghostscript. I therefore wouldn't go below this value either if you plan to use DVI output and convert it using Ghostscript later. As you know EPS files (and some PS) have a `BoundingBox` header which is gives the box as four integer values in `bp`. Anything below `1bp` is therefore down-rounded to `0pt` which causes issues. The additional `HiResBoundingBox` supports fractional numbers but isn't always used by all tools.

The same `bp` unit is used for PDF (which is like (E)PS created by Adobe). I just tested it successfully with a `\rule{.001bp}{.001bp}` which makes `pdfinfo` state `Page size: 0.001 x 0.001 pts` (here `pts` = `bp`). The Adobe Acrobat Reader displays that PDF without errors but seems to only be able to display 3bp x 3bp at maximum zoom of 6400%.

I would not go below 1bp for any output format.

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@xport: What statement that PDF is using bp as well? That the rule works? –  Martin Scharrer Jul 16 '11 at 10:31
@xport: What error message do you get then? I don't get any and it zooms automatically to 6400% and states a size of 3bp x 3bp to me. I'm using Adobe 9.4.2 under Ubuntu 11.4. Also I basically state the same as Herbert, i.e. not to use anything smaller than 1bp x 1bp. –  Martin Scharrer Jul 16 '11 at 10:43
@xport: Thus spoke the PDF ISO norm: "The minimum page size should be 3 by 3 units in default user space; the maximum should be 14,400 by 14,400 units. In versions of PDF earlier than 1.6, the size of the default user space unit was fixed at 1/72 inch, yielding a minimum of approximately 0.04 by 0.04 inch and a maximum of 200 by 200 inches. Beginning with PDF 1.6, the size of the unit may be set on a page-by-page basis; the default remains at 1/72 inch." So PDFs smaller than 3bp x 3bp are not guaranteed to work. –  Martin Schröder Jul 16 '11 at 11:19
@xport: It's always the last user which name starts like that. So Martin Schröder should get be notified. I'm getting notified anyway because I'm the answer author. –  Martin Scharrer Jul 16 '11 at 11:29