5 OpMode and export (technical details)
If you examine export.sty, you will see that the way export{} works is by temporary incrementing the new counter \OpMode. OpMode in actually one of a few new internal quantities added to TEX. It is an abbreviation for ``Operation Mode'' with some of the defined values being 0 (normal .dvi-making TEX), 10 (HTML-making), and 12 (RTF-making). In general you s hould not alter this variable, except for temporary incrementing it by 1, which shifts the compiler to the corresponding Bitmap creation mode. Thus, when OpMode is 11, the TeXpider makes .gif's for HTML, and when it is 13, the TeXspider makes .bmp's for RTF.
Notice that this OpMode shift should be done on an entire TEX box. The sizes of the box will become the sizes of the bitmap image. This has an important corollary that if in normal TEX it is permissible to have boxes with elements sticking out of them, it is a no-no for TeXpider boxes that are converted to bitmapped images. Some examples:
Formula $\!\!=\!\!$ will produce an equal sign (possibly touching the surrounding text) in normal TEX; it will produce just a colon in HTML export (most of the equal sign being cut off).
It is fully permissible (but rarely useful) in LATEX to have a picture environment box that is smaller than the included elements. Such boxes will get truncated.