Visio charts will be scaled from the page size you have used to the correct aize to fill a 35mm slide automatically. Remember not to place anything very close to the edges of the page, as it may be covered by the slide mount.
When you save your file, go to the drop-down menu in the upper left of your screen; choose "File," then "Save As," and save the file as a .vsd file. We have installed on our machine all the fonts which came with Visio as well as with Windows, but not all are active all the time, so let us know which fonts you used to avoid substitutions.
Photographic Specialties is no longer producing slides and transparencies. I have been self-employed for 35 years, but looking forward to retirement since my wife died five years ago. With the decline of conventional photography and the recent recession, the availability of film and chemicals as well as the volume of work has declined to such an extent that it is no longer possible to have fresh chemicals to develop film. I hope that if you still need conventional slides and transparencies, you will be able to find someone who can produce them for you. Thank you for your orders over the years.