Transparency
If you place a graphic on to a page which is in a file format that could retain live transparency you will add that live transparency to your layout. Once placed the graphic will interact with other objects on the page and you can use the graphic-manipulation features of the software to modify the appearance of the graphic.

File formats that you could place into your layout which might contain live transparency include:
Native Illustrator (.ai)
Native PhotoShop (.psd)
Adobe PDF 1.4
Adobe PDF 1.5
Adobe PDF 1.6
Adobe PDF 1.7

If your DTP appication does not understand live transparency (Quark XPress 6.x and earlier)
you should use flattened artwork for placement of transparent content. Most advertisements supplied for inclusion into magazine pages are now supplied as PDF, and your PDF specification should reflect the DTP software to which it will be imported/placed.

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