It is essential that you provide all of the fonts you use to construct your file. If you do not send us the fonts, we will have to substitute something similar and we cannot guarantee that the results will be satisfactory.
Problems with fonts arise because of the wide variety of fonts with the same or very similar names that actually behave quite differently in production. For instance, there are literally hundreds of Times Roman fonts around. You may have Times, Times Roman, or Times New Roman. They may be from Adobe or Bitstream, Apple or Microsoft or someone else. There are Postscript, Truetype, OpenType, Type 1 and a host of others in circulation.
Every one of these fonts is slightly different, and yet Times is also a system font on almost every computer and printer manufactured. As we image your file, we will undoubtedly also have Times on our output devices. However, the possibility that they will have the same font in the same format by the same manufacturer is relatively slim, and the chance that there will be some noticeable difference in how the font renders on different printing devices is quite high.
Page layout programs such as QuarkXpress and InDesign allow you to package or collect your file for output. Along with the document, this will collect all supporting images and fonts. With programs such as Adobe Illustrator, you have the ability to convert text to outlines. If you use any fonts in Photoshop you can flatten your image, which will rasterize your fonts. You should only do this before sending your file. Always keep a layered file separately in the event that you need to make changes later. If creating a PDF from any of these programs, you can embed the fonts, providing a fully inclusive document for output.