To make an export to PDF from a CATIA Drawing you just use save procedure as save a drawing. Just go to File -> Save as -> write the File name and on Save as type form, choose the file format for the file, in this case PDF.
The paper size of PDF will be the same as the drawing format used to in CATIA Drawing. If you want to print the PDF in other paper size, you must install a virtual printer that allows you to use Print function (shortcut CTRL + P) in CATIA V5 without any printer attached to the workstation.
The Print function allow you to choose multiple parameters for paper, for example: Position (Portrait, Landscape, or other rotation), Paper Size (A0, A1, A2, A3, A4, etc.), Scale, Print Quality in DPI up to 4000, etc.
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