Sometimes you want to add emphasis to something in a photo or illustration, but you don’t want to crop it closer or draw a cheesy arrow. InDesign’s transparency and drop shadow features can be used in tandem to create a sophisticated “drop shadow shape” that will strengthen your page layouts.

This is a technique I whipped up for a client recently, though I believe I also remember hearing of a similar technique at the [1] InDesign Conference.

Figure 1: The original image.

Figure 1 shows a standard product shot. This chalice can have one of three different religious emblems on it, and I want to show readers where the emblem is affixed. I could draw an arrow or a circle around the area, but to add depth and interest I’m going to literally circle it with a drop shadow.

Step 1: With the Ellipse tool, draw a circle around the emblem area on the chalice.

Step 2: Fill the ellipse with white and add a drop shadow (Opt-Cmd-M/Alt-Ctrl-M) with black color and X and Y offset of zero. With the two zero offsets, the drop shadow becomes an outer glow effect. Figure 2 shows my styled ellipse; I used a blur of .3 pixels and a spread of 60 to get a strong shadow.

Figure 2: The drop shadow applied to the ellipse.

Step 3: In the Transparency palette, change the ellipse’s transparency to Multiply (or Darken). This knocks out the white and leaves the drop shadow—Figure 3 shows the final effect.

Figure 3: With the ellipse gone, the drop shadow brings emphasis to the emblem.

Thanks to the Screen (or Lighten) transparency setting, you can also create a white outer glow using the same technique. Figure 4 shows the same ellipse, with a Registration fill and white drop shadow, with transparency set to Screen. Filling the ellipse with black won’t work, because Screen and Lighten turn the black into white; a rich black custom swatch will have the same problem. Registration is the only color that will knock completely out and leave the white glow.

Figure 4: With white and black reversed, the drop shadow becomes a white glow.

This technique will work not just with ellipses but with rectangles, polygons and any custom shapes you want. If you want to be really creative, do what I did in Figure 5 and draw the emblem shape with the Pen tool and apply the glow for a truly religious experience!

Figure 5: The combination of transparency, drop shadow and custom shape allows some Photoshop-caliber effects!