Photoshop to InDesign size problem

Question

I created a 3.5 x 2" business card in Photoshop CS3.  I added a 1/8th bleed margin bringing the file size to 3.62 x 2.127" at 300 dpi resolution.  I saved to a jpg file
I created a document in InDesign CS4 3.5 x 2 with no margins and a 1/8th bleed resolution 300 dpi.  When I placed the jpg file in InDesign, it came in 1/8th" smaller on 2 sides.
What am I doing wrong?
Thanks for your help.

Answer 1

Photoshop is a pixel-based program and the images you save have pixel dimensions. If you choose to output to physical media (paper) the size you choose determines the resolution, or physical size of each pixel on the page. Unless you resample, any scaling you choose to do alters the size, not the number, of pixels.
InDesign, which began life as an application for laying out printed pages is very much about physical didmensions, and about type, which for legibility should remain as vectors for smooth printing. A Postscript Point (which is the unit most people use when doing electronic publishing in points an picas) is 1/12 of a Pica. There are 6 Postscript Picas to the inch, so one point is 1/72 inch.
At an effective resolution of 300 ppi, 48 pixels would be .16 inch, or 11.52 pts, reasonable for body text (maybe even a bit large) but too small for most headline applications. If you scale the image, though, and the effective resolution goes down to 200 ppi the the type size goes to about 17pts. It may well also start to show jaggies along what should be smooth edges if it's been rasterized, as would be the case saving as jpeg.
Nobody meant to put you down by pointing out what was wrong with your workflow, and you did ask. We were trying to impress upon you that comfortable as you might be working in Photoshop and saving as jpeg, this is NOT a good workflow for print, even if there is no type involved. Once you've saved that jpeg you've locked the sizes and relative postions of all your design elements, and you've started to throw away good image data with jpeg compression. A high quality jpeg would probably be OK for most commercial print work, but why would you want to save art in a lossy format and risk further damage if you need to edit. Further, jpeg supports neither transparency nor image layers, making future editing a chore.
Since ID supports placing of many other formats, including .psd and .pdf/pdp, those are among the preferred formats for most experienced users. TIFF is also good choice, and an old standby supported by nearly every layout application on the planet. When going to print, the quality of your artwork is paramount. Art you would put on a website and find acceptable is almost never good enough to print except at very small sizes.