11 Replies Latest reply on Apr 18, 2010 2:45 PM by JETalmage-71mYin

    Outer Glow issue in Illustrator CS4

    beach5555 Level 1

      I have a file with a very large logo. probably 4 feet wide by 2 feet tall. I am trying to put the Outer Glow on it so that the logo will show up nicely on a dark background. This however seems to lock up Illustrator, and or, cause the file to be huge. Any suggestions to get the 'glow' I am referring to without this happening?



        • 1. Re: Outer Glow issue in Illustrator CS4
          JETalmage-71mYin Level 3

          Outer Glow is a RASTER IMAGE. You are, no doubt, creating a raster image that is grossly oversampled for its intended reproduction method (although you have not mentioned the target repro method--which you should always do when asking such questions).


          [I'm not beating you up here. I'm just being a little tongue-in-cheek. This is a very common misunderstanding about raster resolution, largely to blame on the far-too-misunderstood rule-of-thumb that is far-too-commonly cited by those without the forementioned understanding as some kind of "universal law" that all raster images ever printed have to be 300 PPI, or else the Resolution Police is going to come and eat your lunch, shoot your dog, slash your tires, roll your yard, and steal your children.]



          The above is vector paths on a 24" x 48" Artboard with an OuterGlow Effect applied. It was done on this worth-its-weight-in-gold, bargain-basement, 3-year old Toshiba laptop with 2GB RAM with Illustrator CS3, Dreamweaver, Internet Explorer, ExtendScript Toolkit, and Windows Calculator all running at the same time. I can drag the LOG-o around or modify it in Preview mode in real time.


          What's the difference between mine and yours? I didn't create a grossly oversampled raster image.


          Nothing printed at 2' x 4' is likely to be printed at a halftone ruling of 200 lines per inch. Even if it were, you don't need a PPI of 1.5 x the halftone ruling for an image that is intentionally a blurry, soft-edged effect. (There isn't any detail in such an image to preserve.)


          No one is going to be viewing a 2' x 4' poster at the distance required to read fine print in an Adobe End User License Agreement. No one in the target audience is going to be evaluating it at a distance of 2" with a 10x loupe.


          The difference between mine and yours is a Document Raster Effects setting of 30 ppi, which is fine for this situation. At the intended viewing distance, even my incredible Lasik-corrected eyeballs are not going to detect the shape of square pixels measuring 1/30"--even if they could detect the tonal difference between adjacent pixels of that size in a soft, fuzzy image.



          • 2. Re: Outer Glow issue in Illustrator CS4
            beach5555 Level 1

            Thanks for your help. My effects setting was 72 ppi, so I will switch it to 30. I am creating a 10 ft wide by 7 ft tall booth and the logo is one element on it. The specs say to have everything at 100 dpi for printing the panels of the booth. Will the 30 ppi for the raster setting work with this?

            • 3. Re: Outer Glow issue in Illustrator CS4
              JETalmage-71mYin Level 3
              The specs say to have everything at 100 dpi for printing the panels of the booth. Will the 30 ppi for the raster setting work with this?


              The 100 ppi guideline is probably a reasonable one...but remember, such guidelines necessarily assume the most demanding situation: a detailed photo.


              There is no detail to preserve in a blurry drop shadow (or outer glow). Its purpose is to be blurry. So your only concern is the posibility of distractingly obvious "pixelation". That means whether the screening method (halftone or stochastic) of the printing method is sampled highly enough to actually render the shape of the square image pixels, and if it is, whether square similarly-colored pixels of that size will be obvious (let alone discernable) at the viewing distance of the booth visitors.


              Now, understand: the above assumes a large format printer that understands vector graphics and raster images and handles them individually (in other words, a PostScript RIP). Not all do. You would not want your vector graphics to be rasterized at 30 ppi. Deliver this as a PDF and Acrobat will handle that if it's not a PostScript device. If the vendor can't print PDF and insists upon a minimum of 100 ppi for "everything", it may be that his old equipment and workflow just rasterizes the whole page (including vector objects) at once and prints a single raster image. In that situation, you could design as you wish, and then just export the whole design as a single raster image at whatever PPI you want. Doing so, you would be rasterizing the vector graphics at the same time, so their edges would have the same "fuzziness" as details in any photos on the page--which should be fine. (You also don't need X-acto-sharp edges on 24" tall text characters.)


              Realize also that you can work at a low Document Raster Effects Resolution setting, and then change it to 100 ppi just before saving or exporting the final delivery file.


              But again, you don't need 100 ppi for a soft, fuzzy, featureless raster effect (drop shadows, glows) on a trade show booth backdrop. You should go with the vendor's specified 100 ppi for any photos that will be included in the design.



              • 4. Re: Outer Glow issue in Illustrator CS4
                beach5555 Level 1

                What I ended up doing was bringing my logo into Photoshop where the background of the booth is. Then it was rasterized, and I was able to put the outer glow on. Is this an ok thing to do?

                • 5. Re: Outer Glow issue in Illustrator CS4
                  JETalmage-71mYin Level 3
                  What I ended up doing was bringing my logo into Photoshop where the background of the booth is. Then it was rasterized, and I was able to put the outer glow on. Is this an ok thing to do


                  It is, if you don't mind your vector graphics also being rasterized, and therefore printing at the same "blurriness" as details in the rest of the design. In most typical cases, assuming modern large-format printing equipment, you would leave your vector objects as vector objects, and your raster objects as raster objects. You would deliver the print-ready file in a format that can include both raster and vector objects (usually PDF).


                  But I don't know any specifics of what your particluar design consist of (other than there's a logo with a glow effect) or of your printing vendor's equipment or specs (other than 100 ppi, assumedly for raster images only).


                  If the whole booth backdrop has one raster image that spans the whole background, that's one thing. If it's just a uniform color that has a few raster images here and there, that's another, and in the latter case I would probably not deliver it as one big Photoshop file (or raster export).


                  If in doubt, you need to discuss with the printing vendor. I often work such projects in individual panels, because I know the display maker is going to be working that way; not actually printing a 10' x 7' image on a single sheet.



                  • 6. Re: Outer Glow issue in Illustrator CS4
                    beach5555 Level 1

                    My entire background is one photo. I have the logo with the outer glow and a line of text. Basically three simple things. I was going to just supply the file in Photoshop. In the past I would supply the file in Illustrator and place in the background photo and logo and create the text in Illustrator. But with the issues I was having with Illustrator this time I went with the Photoshop idea. Do you think this will be ok? I have very limited specs from printer, but they do take Photoshop and Illustrator docs.

                    • 7. Re: Outer Glow issue in Illustrator CS4
                      JETalmage-71mYin Level 3

                      As I said, it will probably be fine, with the one caveat that your vector logo and the line of text will probably be rasterized to the same resolution as the background image.



                      • 8. Re: Outer Glow issue in Illustrator CS4
                        beach5555 Level 1

                        Which will be the 100 dpi. They said everything at 100dpi, so when I opened the logo in photoshop I chose 100 dpi for the resolution. I think this is the correct way to do it.


                        • 9. Re: Outer Glow issue in Illustrator CS4
                          JETalmage-71mYin Level 3
                          I think this is the correct way to do it.


                          One "correct" way to do it, but not necessarily best-practice. Your project will most likely be fine and I'm not being argumentative, but just to be sure you understand for future reference:


                          In principle, think of this kind of thing (and billboards and other large-format processes) as nothing more than a "magnified" view of what you would do for regular offset printing. Regardless of whether the piece is printed as an 8.5 x 11 inch sheet to be held at arm's length, or printed as an 8.5 x 11 foot poster that reads like an 8.5 x 11 inch page when viewed from 50 feet away, there's good reason for why programs and workflows are designed to accommodate separate raster and vector objects in the same design and postpone final rasterization until the final imaging stage. Optimum results are obtained when the vector objects are not pre-rasterized.


                          Large or small, a printing device has a fixed "hardware resolution." It can only print a dot of one size (a printer spot). Each individual printer spot is either turned on or not, so they really can't render continuous-tone images (like photos). To print continuous-tone artwork or photos a printing device has to use some kind of toning scheme (like haftoning) to construct larger dots that the viewer's eye blends into graduated color tones. The algorithm varies either the size or the frequence of those much larger dots.


                          But where do those larger dots come from? The printing device has to "build up" each of those halftone dots out of its fixed-size printer spots--all of which you probably know, but which now brings us to the difference with vector elements.


                          Vector artwork (including text) is advantageous in that it does not have to be rasterized before being sent to the imaging device. So while the sharpness of a contone photo is dependent upon the size of the large dots (the halftone dots), vector graphics are not. Their sharpness is dependent upon the much smaller printer spots.


                          That's why, for example, if your design was built as a full-page magazine ad, and you pre-rasterized the logo and type down to pixels in the background 225 PPI image, the ad may very well appear rather sub-standard blurry, especially if the type is small. Well, the same principle really applies at any size. (Again, though, as described, the blurring of the vector edges will not likely be a problem on your trade show booth; but it could have been sharper. You should still consider the difference important in future work.)


                          All that is why you can have in the same printed design (be it a page in National Geographic or a highway billboard), raster photographs at a relatively "high" ppi, raster effects (like drop shadows) at a "low" ppi, and vector objects including everything from logos or other artwork to 6 pt. disclaimer text that actually gets rasterized at the much higher spi (the hardware resolution of many imagesetters is typically 3000 or higher)--each with best-practice results. That's why we don't just always willy-nilly flatten everything, including text and other vector elements down to a single raster at a single ppi, but instead pass individual objects--some raster, some vector--to the printing engine.



                          • 10. Re: Outer Glow issue in Illustrator CS4
                            beach5555 Level 1

                            You have convinced me then. I am going to try my best and submit the file in Illustrator. I will place the background photo in Illustrator, please the Illustrator EPS logo in Illustrator and create the text in Illustrator. I think this will make the best file for the printer. I will though change the raster effect setting to 30ppi for the outer glow. Thanks so much for your explanations....I am still learning. Every bit helps.

                            • 11. Re: Outer Glow issue in Illustrator CS4
                              JETalmage-71mYin Level 3

                              Not to belabor this, but since you're planning to re-do it (was not my intention to convince you to do that):


                              Especially given the overall size, involving a single full-span background raster image, and the simple content, this is my typical practice for that kind of thing:


                              1. Build the background image in Photoshop, as I think you already have.


                              2. Set up the full-size AI document, with guides at the panel edges, any necessary bleeds, etc. (It's good to mark where the panel seams are, even if you are not going to build individual files for the separate panels. That often lets you tweak the position, for example, of text so that the seams occur between words.)


                              3. From Photoshop, save a low-res version of the background image (or just take a screenshot) to use "for position only" on a background layer in Illustrator.


                              4. In Illustrator, position the vector objects and text without raster effects. Also draw a temporary, small, filled, unstroked square aligned to two opposite corners of the whole layout's guides. (Assuming the EPS logo you mention is simple vector content, I would Open it, not place it as a link.)


                              5. Copy any objects created in step 4 which require a raster drop shadow, glow, etc. and the two small squares.


                              6. Switch to Photoshop. Paste. Select Rasterize in the resulting dialog. Proportionally scale to the corresponding guides in Photoshop. (The two tiny squares ensure proper position of all the other elements.) You can do the scaling and positioning while it's still selected; it doesn't actually get rasterized until you "nail it down."


                              7. Apply the drop-shadows, glow, etc. as a Layer Style. In the Layers Palette, split the effect(s) as separate layer(s). (There's a comand for that.) Delete the pasted content. That leaves the original background object and the raster effects.


                              8. Flatten the layers. Now you have one simple background raster image, with the shadows, etc., part of it. Delete any unnecessary alpha channels, etc. Save as TIF.


                              9. In Illustrator, delete the low-res FPO. Place the TIF in Illustrator. The vector objects and text are still in their intended positions and their shadows, glows, etc., are actually part of the background image.


                              10. Save the Illustrator document. Save a Copy... as print-ready PDF. Send the PDF to the vendor.


                              Some will argue that is rather old-school, and go on about so-called Smart Objects and "why don't you just apply the live effects in AI?" yadda, yadda, yadda. Well, it is somewhat old-school, but it is also rock-solid reliable. No automatically generated clipping mask, no automated slicing, no unpredictable stitching artifacts--no ugly surprises. Just a clean, efficient file that you won't lose sleep over. And the behavior of Illustrator doesn't slow to that of cold molasses.