VRML files are by definition in meters, but many application seem to ignore that and export in mm, inches or other units. Shapeways will always interpret VRML as being in meters and refuse everything else. You can certainly resize everything in your software, but that may have negative impact on the precision of the exported mesh and lead to other problems. Here is what we found: Create and export a simple 10x10x10 mm (or inch, if you like) cube in your favorite software. Shapeways will moan at you and claim that the model is too big. From the reported numbers, you can easily determine the scale factor. Ours is always 0.001, lovers of Imperial or American units have a little more work to do. Record the scale factor in a little text file for later use, in this format: Open the VRML file in your preferred text editor. Wordpad will do, Notepad may be slow. You will find something similar to this: Paste the content of your scale file into the VRML, right after the first line. You may also want to delete the extraneous comment lines: Scroll to the very bottom of the VRML. At the very end, enter this: Done. Save the file, upload and enjoy.