9 Replies Latest reply on Mar 26, 2010 2:22 PM by snowgage

    Creating an inner-glow with a transparent center


      Howdy...  I am working on different symbology techniques for a map I am working on.


      Usually, when I display land ownership, I'll use diffent colors for each type and reduce their opacity as to see the underlying landscape.


      What I'd like to do is symbolize such that the color is thick on the edge of a polygon and then fades away towards the center.  In the image below I can explain what I am trying to do.  The polygon in the upper left has an inner-glow applied to it.  If it could be fading to transparent rather than white in the center, this would be perfect.  The middle polygon simply has a radial gradient which is too circular for my taste. 


      Can anyone suggest how to achieve the look of the inner-glow but use no-color as the center color?



        • 1. Re: Creating an inner-glow with a transparent center
          John Mensinger Adobe Community Professional & MVP

          Select that upper shape and set its blend mode to Multiply. That will render the white areas effectively transparent, but it will also affect the green color, so you may have to adjust from that point to get the color(s) you desire.


          Perhaps a better option would be an opacity mask. You would make your color overlay shape one solid color, then overlay that with a congruent shape containing grayscale values that dictate opacity/transparency.


          Explained by Mr. Golding here:



          • 2. Re: Creating an inner-glow with a transparent center
            JETalmage Level 6

            Use a Blend between an opaque and a transparent path to define an ArtBrush that can be applied to any shaped path:





            1 person found this helpful
            • 3. Re: Creating an inner-glow with a transparent center
              jay fresno Level 2

              1. Draw a square-corner square.

              2. Draw a round-corner square that is smaller than the first square.

              3. Fill both squares with the same solid color. No Stroke.

              4. Change the round-corner square to zero transparency.

              5. Center the two shapes.

              6. Select both shapes and choose Object > Path > Add Anchor Points.

              7. Blend the two shapes using Specified Steps. About 100 steps should work well.


              I wasn't able to upload images to the forum. See example at:


              • 4. Re: Creating an inner-glow with a transparent center
                Wade_Zimmerman Level 6

                For an ellipse I would use a radial gradient from less than 100% white to a completely transparent white.


                for a rectangle I outline a thick stroke and fill it with four fills all transparent (less than 100%) white to a completely transparent white.


                You can the control the transparency of each side and well as the gradation of the gradient.


                Also the thickness of the gradation each side.


                Like thisScreen shot 2010-03-20 at 2.11.33 AM.png

                • 5. Re: Creating an inner-glow with a transparent center
                  snowgage Level 1

                  I've been working on this a bit more and not yet found the method I am looking for...


                  In the image below the shape on the left is my original where I'd like to apply the effect.  Creating a custom brush using a blend between an opaque line and a transparent line creates the brush effect I'd like to use.  Unfortunatley when I apply it to my shape I enconter problems at the corners.  How can I get this effect to apply around the corners of the object?



                  I've also tried using the multiply effect of the inner-glow command.  I cannot get the inner color as transparent.  Not sure what I am missing on this one.  See example below.  Using multiply, I can get the inner color to be anything but transparent.  Am I missing something very obvious on this?




                  thanks a lot in advance!





                  • 6. Re: Creating an inner-glow with a transparent center
                    Jacob Bugge MVP & Adobe Community Professional



                    You may round the corner(s) just enough to get rid of the (visible)  discrepancy; it only takes a small radius.


                    To do that, you  may use the Effect>Stylize>Round Corner, or if you wish to create  two Anchor Points on the path (at each corner), you may use the Round  Any Corner script here: http://park12.wakwak.com/~shp/lc/et/en_aics_script.html

                    • 7. Re: Creating an inner-glow with a transparent center
                      John Mensinger Adobe Community Professional & MVP

                      I've been messing around with this a bit myself, and I'm convinced you'd get the best result with my initial suggestion: an opacity mask.


                      Leave your shape a solid fill color, then duplicate it in place, (Ctrl-C, Ctrl-F). Fill the duplicate with black, then apply the Inner Glow Effect using white. Now select both copies of the shape and choose Make Opacity Mask from the Transparency Panel menu. If the result is backwards, select Invert Mask in the Transparency Panel, (or go back to the Inner Glow effect and reverse your edge/center choice). The mask and its Inner Glow effect remain live and adjustable, and you can also change the fill color of the masked object. If you haven't tried it yet, give it a quick go.

                      • 8. Re: Creating an inner-glow with a transparent center
                        JETalmage-71mYin Level 3

                        Use parallel paths (simple or compound) and Blend, with the inner path set to zero Opacity, as already suggested. As always with Blends, for best results, take the time to ensure that both paths have the same number of anchorPoints.



                        (Oh fercryinoutloud; here we go again with these stupid automatically created multiple forum accounts!)



                        • 9. Re: Creating an inner-glow with a transparent center
                          snowgage Level 1

                          Nice!  The inner glow on analogous B/W shape, then used as transparency mask was the ticket!


                          Thanks for the help everyone.. I am just not sure I like the way is looks...



                          I am displaying land ownership... Often I'll just use a color-specific fill with transparency... I often have elevation depended shading on my topography and wanted to keep it visible.

                          ..  Not sure if I like the effect yet..