Have you ever printed a design and had a funky result? It’s not uncommon to have a printed output look different than an intended design, and the culprit is typically transparency. It’s important for designers to understand how transparencies work to ensure that printed outputs match indented designs.
Types of Transparency
- Feathering an object creates a soft edge by fading the object’s color(s) from opaque to transparent over a user-defined distance.
- Drop Shadow
- When you apply a drop shadow, the program duplicates the object, applies a feather and places this duplicate behind the original object.
- Blending Mode
- Different blending modes allow designers to manipulate how colors of an object blend with colors of underlying objects.
- Changing the opacity of an object allows a background or underlying images show through the object. You can vary the degree of transparency from 100% (opaque) to 0 (transparent).
Most of the errors created from transparency use result from the flattening process. During the flattening process, all overlapping areas are separated and converted to rasterized opaque images that (hopefully) retain the desired appearance.
As you can see in the above image, rather than considering these circles as three objects, the program considers this as seven objects. This is why it’s possible to see lines in overlying images after they have been flattened.
The more complex the overlap, the more objects generated during the flattening process. Here, you can see that the flattening process took these four shapes and generated 26 separate objects. Keeping your transparencies as simple as possible is a good way to avoid errors while flattening.
You can manipulate how your program flattens documents by changing your transparency flattener presets. To learn more about working with these presets, see Adobe’s help page here.
CMYK inks are transparent so that they can mix and create other colors. PMS (spot) colors are opaque and intended to stand alone when printed. Because the PMS inks are opaque, using them with transparency effects almost always creates an undesired result when printed. The PMS object will either simply not print, or the RIP process will attempt to create a CMYK equivalent, usually resulting in a shift in color. If you want to use transparency effects with a PMS color, it’s best to convert the PMS to a CMYK equivalent yourself while designing.
During the flattening process, if text is included in a stack with transparent objects, the text will be converted to paths. This can slow down the printing process and even change the appearance of the text. If you notice that parts of text are fatter than others when printed, it’s most likely because those parts are under a transparent object and being converted to paths. The best way to avoid these problems is to bring all text to the top layer unless the desired result is to have the transparency manipulate the text.
Having the text on the top layer gets tricky while using text wraps. In most programs, the object with text-wrap properties needs to be above the text that it modifies. If you have a drop shadow or feathered edge that runs into the text, that text will be converted to paths when printed. To avoid this, create an empty frame the same shape as your object and apply the text wrap to that frame. Put the text above the object, and the empty frame above the text.
- To reduce the possibility of a color shift, use the same transparency blend space as your output space.
- View the print result on-screen by enabling Overprint Preview.
- In Illustrator, be sure to apply transparency effects as effects, not as filters.
- Always consider how stacking order effects transparency results.
- Be careful when using transparency with PMS (spot) colors.
- Don’t feather small type or fine serif or script fonts.
- Keep your designs simple.
- Move all text layers to the top.
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