9 Replies Latest reply: Nov 14, 2010 9:56 PM by Wade_Zimmerman RSS

    Shape jagged edges issue?

    30eleven Community Member

      I'm creating objects in illustrator (CMYK, 300dpi) for print purposes and the thing that bothers me is the jagged edges with a light pink color between the fill and stroke of the shape (see image) at any zoom level.

       

      This shape, created in Illustrator, is being imported into a Photoshop collage at the same resolution on a dark grey background, where the jagged edges become even more striking.

       

      Will this look as it should when it comes out of printing house? I know there's a difference between shape handling in Ai and Ps because of the different output media for each another...but still the screen appearance is disturbing.

      edges.jpg

        • 1. Re: Shape jagged edges issue?
          Jacob Bugge CommunityMVP

          30eleven,

           

          I'm creating objects in illustrator (CMYK, 300dpi) for print purposes and the thing that bothers me is the jagged edges with a light pink color between the fill and stroke of the shape (see image) at any zoom level.
          Just to state it before someone complaints: it is PPI (pixels per inch), not DPI (dots per inch), but why rasterize in Illy?
          Also: are you sure that is the right resolution, if you must?

          Will this look as it should when it comes out of printing house? I know there's a difference between shape handling in Ai and Ps because of the different output media for each another...but still the screen appearance is disturbing.

          It may very well, especially if you Anti-Alias in case you export/save to a format where it is relevant (JPEG, PNG, GIF).

          • 2. Re: Shape jagged edges issue?
            30eleven Community Member

            Just to state it before someone complaints: it is PPI (pixels per inch), not DPI (dots per inch), but why rasterize in Illy?
            Also: are you sure that is the right resolution, if you must?

            Sorry, I mixed up the PPI and DPI thing. I won't rasterize anything in Illustrator, I just have to use it on a Ps document.

            Resolution is right.

             

            It may very well, especially if you Anti-Alias in case you export/save to a format where it is relevant (JPEG, PNG, GIF).

            Yep, it will be a JPEG.

             

            The main problem is that it looks like [censored] on screen and I can't figure out due to what it's like that.

            • 3. Re: Shape jagged edges issue?
              Monika Gause CommunityMVP

              This is due to the rendering of 100 K in CMYK color mode. Won't happen with rich black or in RGB mode.

              • 4. Re: Shape jagged edges issue?
                JETalmage Community Member
                function(){return A.apply(null,[this].concat($A(arguments)))}

                I'm creating objects in illustrator (CMYK, 300dpi) for print purposes and the thing that bothers me is the jagged edges with a light pink color between the fill and stroke of the shape (see image) at any zoom level.

                 

                I'll assume your screenshot is from Illustrator, not from Photoshop after importing the AI elements. That is, I'll assume that both the red shape and the black shape are native to Illustrator, both are vector paths with ordinary fills applied (no raster-based effects), and you want to bring both of them into Photoshop. The undesirable "light pink" is what you're seeing in Illustrator.

                 

                First, understand that in Illustrator you are not creating pixels. You're creating paths. Paths are mathematically-defined curves. You apply fills, which are just another kind of command, not pixels. Now...as you work in Illustrator, Illustrator has to display what you are creating on your monitor as pixels, even though what it's creating are not pixels. In other words, it's "printing" the mathematical shapes to your monitor. Your monitor is acting as the "printer." The monitor has pixels, but your objects (the paths) don't.

                 

                By default, Illustrator "prints" to your monitor using an algorithm called anti-aliasing, which is just a routine that disguises the inhernent jaggedness of the large, crude monitor pixels in order to make the on-screen appearance smoother.

                 

                You can turn that anti-aliasing behavior  off in Illustrator's preferences. Turn it off and you'll see the edge between the black and red objects become more jagged, but the pink goes away. The degree of jaggedness will stay the same regardless of zoom, because the jaggedness you're seeing is the physical jaggedness of the pixels of the output device (your monitor).

                 

                Well, the same principle applies to anti-aliasing. You say the undesirable light pink along the edges occurs "at any zoom". (Again, I'll assume you're doing the zooming in Illustrator, not Photoshop.) So if you have antialiasing turned on, and if you zoom in alot, you still see the unwanted pink edge. But now ask yourself: Does the pink edge actually grow larger as I zoom in? If it doesn't, it's not "real"; it's just the result of the anti-aliasing routine that Illustrator is using when it "prints" to your monitor.

                 

                Further, you already know that you have not created any pink objects, right? So the unwanted pink edge is just an anti-aliasing artifact when viewing the artwork in Illustrator on your monitor. That is, since you haven't created any pink objects, there won't be any pink objects when you save the Illustrator file.

                 

                Now...all the above applies while working in Illustrator. Read on...

                 

                function(){return A.apply(null,[this].concat($A(arguments)))}

                This shape, created in Illustrator, is being imported into a Photoshop collage at the same resolution on a dark grey background, where the jagged edges become even more striking.

                 

                The artwork is "being imported" into Photoshop how? If you paste or import the vector artwork into Photoshop, it is going to be rasterized (converted to pixels). If you export the artwork from Illustrator to a raster image, it is going to be rasterized. Either way, somewhere along you are going to be presented an option to let you choose whether the imported or exported vector paths use anti-aliasing when that rasterization occurs. If you choose to apply anti-aliasing during the export or import, then yes those pink pixels are going to actually exist in the resulting raster image. However, the degree to which they are visible will depend on the size of the pixels relative to the scale at which they are printed.

                 

                So again, ask yourself the same question, but this time, in the context of Photoshop: When I zoom in alot (in Photoshop), does the unwanted pink edge grow larger? If it does, it's real pixels, and yes, it will print. But again, how visible it will be in print depends on printing scale.

                 

                Understand also: Such edges are not necessarily undesirable. In raster imaging, one often goes to great lengths to add such "edges" between adjacent pixels of different color. That's essentially what sharpening does. Sharpening actually alters the colors of adjacent differently-colored pixels so as to increase their difference. In the case of any color against black (since black can't get darker), this would result in an "edge" of pixels that are lighter than the non-black color.

                 

                function(){return A.apply(null,[this].concat($A(arguments)))}

                Will this look as it should when it comes out of printing house?

                 

                That's where you have to define "as it should". When you rasterize the vector objects into another raster image in Photoshop, it all ultimately becomes one raster image. Zoom in and see if the pink pixels are actually there.

                 

                function(){return A.apply(null,[this].concat($A(arguments)))}

                I know there's a difference between shape handling in Ai and Ps because of the different output media for each another

                 

                That doesn't make sense. If this is something that you know, you need to find a better way to state it.

                 

                function(){return A.apply(null,[this].concat($A(arguments)))}

                ...but still the screen appearance is disturbing.

                 

                On-screen appearance is always disturbing. Anti-aliasing is just one flavor of disturbance. Color accuracy is another. The fact is, a monitor is a very very different kind of output device from a printing press, and the two are never going to look the same. That's why the answer to whether it prints "as it should" lies in the printed results, and that's where you have to look for the answer. But if you send a raster image to a printer, if the unwanted pink pixels are actually there in the image file, then yes, they will print. You can determine whether they actually exist in the final raster image by examining it in Photoshop.

                 

                JET

                • 5. Re: Shape jagged edges issue?
                  Wade_Zimmerman Community Member

                  Let me ask you something do you see this pink glow when you view your posed screen shot here on the forum?

                   

                  there is a point in time when 300 ppi (not dpi) will show up by increased magnification.

                   

                  Then if you see this pink artifact that would be interesting because from what you post I do not see it.

                   

                  Does this artifact scale when you magnify it if ti does not then it is simply a display artifact that is showing for you but not showing for me.

                  • 6. Re: Shape jagged edges issue?
                    Wade_Zimmerman Community Member

                    You guys see an artifact in the screen shot?

                    • 7. Re: Shape jagged edges issue?
                      30eleven Community Member

                      Thank's to Monika and JET.

                      Both of your answers were very helpful. The 100k did the artifact, but the reply of JET explained a lot of things to me, that I didn't understand before, so again, thank you very much.

                      • 8. Re: Shape jagged edges issue?
                        tromboniator Community Member

                        Wade,

                         

                        I'm guessing that the fill is the red part, the stroke is the black part, and the shape is the whole thing that we see in the image. If I zoom the screen view fairly radically the anti-aliasing between the red and the black might be described as pink, not very different from the red/white boundary, possibly a bit less obvious against the white. I'd be more apt to call it gray, but pink works. To my eye it's no more offensive than the red/white or the black-white boundaries. So, yes, I guess I see it.

                         

                        Peter

                        • 9. Re: Shape jagged edges issue?
                          Wade_Zimmerman Community Member

                          tromboniator wrote:

                           

                          Wade,

                           

                          I'm guessing that the fill is the red part, the stroke is the black part, and the shape is the whole thing that we see in the image. If I zoom the screen view fairly radically the anti-aliasing between the red and the black might be described as pink, not very different from the red/white boundary, possibly a bit less obvious against the white. I'd be more apt to call it gray, but pink works. To my eye it's no more offensive than the red/white or the black-white boundaries. So, yes, I guess I see it.

                           

                          Peter

                          Well, if that's the way it gonna be… I wont' forget!