Fonts supported by the PDF created


Recently I have been working on some conversions from OVE files (from Overture) to PDFs using PDFCreator 1.2.3. In my files there are several fonts used including Helvetica and Gill Sans MT. However after conversion I cannot see the words using the above-mentioned fonts displayed correctly. Do any know what is the reason behind or if there are any restrictions on the fonts of text in the files to be converted to PDF? Thanks.