Join Russell Viers for an in-depth discussion in this video What is flattening?, part of 11 Things Every Newspaper Should Know About PDFs.
One of the biggest problems we have with PDFs is this flattening, or let's broaden that by saying transparency. And maybe the problem is unflattening. Well, I find that the biggest problem is just not knowing what it is. Once you understand it and how it works then all of a sudden, it makes sense and you go okay in this case I'm going to flatten, in this I'm not going to flatten. I don't need to here, I do here. Let's just take a look at flattening is. This is an unflattened file. Let's go to file > > properties, created Indesign, exported using the PDF library, not printed and distilled, and its PDF version five or newer, which tells us that if there is any transparency that was built into that file, it's not flattened.
What's transparent? Well, a drop shadow applied in the design. An opacity control, or a feathered edge, all of these things you see in front of you on this document were created in InDesign. But it could also include a photograph out of Photoshop with a knockout on a transparent layer, something out of Illustrator with transparency like a drop shadow, a PDF with transparency placed in another InDesign document. So there's lots of times when you have transparency.
This is unflattened. Hm, so what does that look like? Let's go to tools, and let's go to the edit object tool, and watch what happens when I grab that box and move it. Wait a second. Yeah. This is just like moving different objects on a page. This is easy enough. I can move that picture there. There's the drop shadow, I can move it within that box. I can take this picture and move it and actually get rid of that stuff if I don't want it.
So as you can see, an unflattened file still retains some of its original characteristics from InDesign which gives us more edit-ability. But what happens when we go to a Flatten file? Same tool. Edit object. Watch this graphic here as I move this. Hmm. Hmm. Flattening, unlike Photoshop when you flatten, which basically takes all the data and just rasterize it into a single layer, this takes vector data and tries to keep it vector by chopping it up into smaller portions. If it's Raster and it interacts with something else, it may give you something like this.
So visually, it looked the way you wanted it. But when you get in here and start working on it, you realize: There's a hole in that photograph. Look! Can you see through it? There's a hole there. It cut a hole there for this box to fit in, so that this could fit in there, and this text could go on top of it, and when we output it it looked correct. Well,LAUGH that's fine if you don't want to edit. If you want to make any edits, you've got some problems here.
So just know that flattening takes your art and chops it up into these little sub regions, so that it renders properly. That's what flattening does. Sometimes it can cause you a real problem. If I go to this file, which has been flattened, and I think that photo is too dark, I just think it's too dark. So I go to tools, edit object, and if I click on that to extract it to lighten it. Well, this flattened file has been chopped up into all these little subregions so, good luck. Good luck lightening that photo.
Let's undo that back to where it was, and you can that it's going to take a lot of time to extract all of these and, and manipulate them. I could try to open the entire page and do it but again if it weren't flattened this would be a single object that I would be dealing with and this would just be simple text that I would be extracting. So flattening makes some permanent decisions on your file that aren't made if it's not flattened. So it's an important distinction that flattening, a lot of people want to flatten so that they have safer production downstream, just know that it creates more problems when you get into the PDF editing process.
- Checking out the PDF
- Digging deeper with the Output Preview panel
- Simple fixes with the TouchUp tools
- Converting colors
- Managing transparency
- Working with fonts
- Preflighting PDFs
- Repairing PDFs with Photoshop and Illustrator
- Exporting vs. printing and distilling