Sort of.... The best practice is to do no enlargement in the rip, do it all in photoshop, if you do the enlargement in the rip, stick with the common factor idea. IE, if you are going to send a file and double its file size in the rip, make sure its dpi going into the rip will work out well with the enlargement factor and the native resolution of the machine. So, a 360 dpi image doubled in the rip works out to 180 which is a good correlation to a 360/540/720/1440 machine. So if you output at 720 dpi at the printer, it will be multiplying by nice round numbers (always the goal).
I think I'll post my workflow for photography->Illustrator->photoshop->Rip which will help contextualize a lot o the info. I actually came to digital printing from having gone to art school and worked as a commercial illustrator and art director. A lot of the image stuff I learned (especially from 3D computer graphics stuff) really helped me wrap my brain around printing better. The rendering process with 3D stuff is basically analogous to ripping files.
I'll attach a design I recently did where I did the photography, design and printing using what I feel is the best workflow for achieving a fast rip, and excellent results.
1) Photography
First things first, I shoot everything right now with a Sony Alpha 10mp Digital SLR in RAW only. I use a Sigma 28-300 (good general purpose lens, not amazing quality but versatile) with B+W MRC circular polarizer. The photos for these images were shot outdoors. I'm not a professional photographer, and my lighting equipment is pretty limited, so on big stuff I just hope for a sunny day
2) Photo Editing
I use CS3, and Bridge to bring all my photos in via camera raw. I use camera raw to do baseline adjustments. If I need to layer up an image to refine appearance, I try to do the adjustments for the different layers (at least roughly) using camera raw, and then I combine them in a psd. I synthesize the different raw processed images masking to reveal the better sections of each component. Sometimes I bracket via ISO to extend the dynamic range. I use the same principal, bring in each shot via camera raw and try to do as much there as possible, if necessary doing several raw versions to synthesize one image later. Of course camera raw has a lot of limitations, so regular photoshop workflows apply once you've done the best you can.
3) Layout
For higher end outputs, I work 1:1 in illustrator despite the aforementioned issues. The reasons for this will become clear soon. All raster artwork is brought in as linked files. This is very important. After finalizing the layout, I select each piece of raster artwork from the linked file pallet. I then write down the file name and the size it has been scaled to (print size not pixels) in th layout.
4) Back to photoshop.
I then go and open all the photos again in photoshop. I resize/re-sample them to the sizes recorded from illustrator using Genuine Fractals Print-Pro. The resolution is re-sampled in Genuine Fractals to 360 dpi at the same time. Also, I use the unsharp mask less than I used to in photoshop and do alot of my sharpening adjustments in GF. The tools in genuine fractals print pro are awesome. I then use Noise Ninja (optional) to help work out any grain from higher ISO shots. I find that I now use Noise Ninja in moderation on almost all my photos. I then flatten and save a new version of the file.
5) Back to illustrator
Open the layout in Illustrator. Go to the links pallet and replace all the links with the images re-sampled/sized in Genuine Fractals. They will directly replace the versions we started with and require no positioning etc. In fact, in the editing environment you won't notice any difference, but it makes a huge difference in the print. The issue we're avoiding is that Illustrator does an abysmal job of dealing with raster artwork especially scaling/sampling. We basically handle that for it by doing the work in photoshop with the genuine fractals print pro plug-in. Once you've finished replacing the links save a new, final version of the illustrator layout. Make sure you add crop marks and that all of the design makes it on to the artboard.
6) One more time to photoshop
Open the AI file in photoshop (Illustrator sucks for exporting raster artwork and often will throw memory errors due to adobe's incompetence in handling swapfiles), when the import/open illustrator file dialog comes up select crop box and set the rasterize resolution to 360 dpi. Make sure that your dimensions are the same as your AI file (they should be by default). The idea here is that we've done all the resizing/re-sampling for photoshop so it won't butcher your nicer photos with fugly bi-cubic re-sampling. Once it finishes opeing, save it and your done.
Now just RIP it!
From my experience, this is the best way to deal with resized/resampled artwork in a real world layout scenario. The file linking in illustrator is the key concept and makes it a lot easier as you don't have to nail down your image sizes until after your done tweaking your design.
Also, good color management practices apply throughout. I am managed from in camera on out (Sony has Adobe rgb 1998 as a color space for the camera) although its moot if you shoot raw. I am currently profiling with an X-Rite DTP 41 (Series II USB) and an X-Rite DTP92Q (yes I'm still in the stone age with viewsonic and mitsu CRT diplays).
Hope this was useful, the print reallys looked great. I printed them on my Mimaki JV3-160s 6 color using triangle JVS inks with wide gammut magneta and light magenta onto arlon dpf 4000 film and mounted them to corrugated plastic. I printed 720x720 16 pass Bi-Di. Solvent will never look like an aqueous art print, but it can get pretty close, are at least pretty darn good with a good workflow.
