For a several releases now, Photoshop has supported vector output. Vector graphics can, of course, be resized without any distortion or pixelization.
There are three ways to retain the vector data in your Photoshop files.
1. Save your file as a native PSD file. The data is retained in the file but is not usable by a secondary application like InDesign. Your graphic will be rasterized when it is placed in the page layout.
2. Save your file as an EPS files. Unlike the PSD file, the vector information is usable when the file is placed and scaled in your page layout. The drawback is that when the file is re-opened in Photoshop, all the vector data is lost.
3. Save your file as a Photoshop PDF. To clarify things for your prepress provider, manually change the file extension from “.PDF” to “.PDP”. This is really the only format that can make the round trip without losing its vector data.
As in so many other places in print and web design, faux type styles should be avoided. “Faux bold” and “Faux italics” will be immediately rasterized as there is no vector information to embed.