First off, I must apologize for not posting at indesignsecrets.com in such a long time. At the beginning of the summer, my wife and I had our second son, Theodore Rocco LoCascio. Since then, it's been a lot of sleepless nights and extremely busy days as we care for our new little one and our 2 year old son, Enzo. Thankfully, things are starting to get a little easier (only one late night feeding now...yawn), and I now have the time and energy to contribute to my favorite blog site for creative professionals.
A lot has happened during my "maternity leave." We now have a new and improved site design here at IDS, and we also have a new version of the Creative Suite! How cool is that?
There are a lot of great new features in InDesign CS4, and one that I especially like is the new Link Info section of the Links panel. You can now access a whole bunch of information about a specific link by selecting it in the document or from the Links panel list, and then referring to Link Info.
You can choose which options you'd like to display in the Link Info section by selecting them in the respective Panel Options dialog box. Some of these options include: ICC profile, color space, link path, and layer position. The options that I especially like having quick access to are actual PPI, effective PPI, and scale percentage.
You've always been able to access actual PPI and effective PPI readings for a selected link from the Info panel (and still can). However, if you're like me, and are really bad about referring to the Info panel, then you'll love the added convenience of being able to determine a scaled image's resolution right from the Links panel.
The actual PPI reading tells you the resolution of the image at 100%, whereas the effective ppi tells you the resolution of the image when printed at its current scale percentage. Therefore, if you place an image at 100%, then both readings should be the same. Scale the image down and watch the effective ppi value increase.
So let's say you place an image with an actual ppi reading of 72. At 100% the image resolution would be too low for print. You can tell this by the effective ppi value, which should also be 72. So how far do you need to scale the image down before it's suitable for high resolution print? Try scaling it down until the effective ppi value is at least 220. When the effective ppi reading is 220 or higher, then you're safe.
In the old Quark days, I used to calculate resolution by opening my placed images in Photoshop and entering new print size values in the Image Size dialog box, without actually resizing them. This can still be done of course, but why leave InDesign if you don't have to? And now in CS4 with these ppi values displayed right in the Links panel (which I almost always have open), I always know what my placed image resolution is.