Logo design: shape overlap?

Question

I am in the process of cleaning up a relatively complex logo, and am unsure as to what the best way to manage the joins between different colors. Should I leave the vector shapes in such a way as they overlap, to prevent potential gaps when printing? Or should I leave them so that only the visible part is the vector outline to simplify and prevent potential printing problems?

Are there any advantages or disadvantages of doing it either way?

To explain my point a bit better I've made a graphic. In Option A the blue background overlaps behind the dark stroke, in option B the edges of both shapes barely touch. In non-outline mode they look identical.

Answer 1

Watch out for overprints

The only risk with the overlapping approach is when you over-print. With a good printer, they'll take care of it and it won't matter. With a bad printer you have a whole host of things to worry about anyway so just find a good printer (^_-)

Best practice

I think it's best to leave the overlap in place. I say this for the simple fact that very tight tolerances are more likely to result in error. For instance, you (or some junior helper) accidentally make a small shift to one point. This small shift is difficult to see except at the highest zoom. Extrapolate this potential over the myriad shapes and points of a complicated piece and things can get messy.

Better best practice

If possible, just use one shape. In this case, you have a fill and a stroke. If you can get the result you're after with one shape, you should do it. Alternatively, you might be able to use a mask shape where the fill color has very loose tolerances (ie large overlap) to make avoiding error a simple matter.

Answer 2

The overlaps will have no bearing on printing. What you see in Preview Mode is what is printed. That is what "preview" refers to. It makes little difference if you remove the overlaps or not.

Upon production output, colors are trapped to each other. The area of visible color is what is output, not the shape boundaries. It doesn't really alter anything if there's an overlap or not for most objects.

Ultimately it's a matter of preference and there's no solid reason one needs to be concerned abut the overlap for most print production.

Now for signage and vinyl cutting you would not want the overlap. Because with signage and cutting the shape boundaries are used.

In terms of logo delivery to clients, I remove the overlaps by flattening and merging artwork. This simply makes editing more difficult and there's no viable reason a logo should be edited by a client. But I always retain a "live" version of everything so I can easily edit it later if needed.

Answer 3

Printing

When printing the rasterization engine does quite many pixels. Thus it is not likely to generate a gap. A gap can still form from misalignment of plates but this would happen even if you would overlap because the rasterization process would still overlap the elements. That is unless you overprint

Other considerations

Printing aside, overlap is better for many software engines. Software engines do need to anti alias the edges. This process can be done with 2 methods:

• Computing mathematical coverage
• Oversampling

Oversampling is computationally intensive, but is not very likely to cause a gap just like printing. Because its computationally intensive its often avoided.

So nearly all SVG  and PDF  renderers out there work with coverage computation. Coverage computation is prone to aliasing error because it guesses what the background color is wrong if you do not overlap. So when your client complains about white hairlines, you should know overlap would have helped. So the example form this post:

Image 1: preview of firefox. Source SVG: http://imgh.us/tris.svgz

Image 2: preview of firefox w overlap. Source: http://imgh.us/tris2.svgz

Downside of the overlapped art is that its easier to rebuild and modify should the client want to do so against your wishes. Also beneficial to you had the source gotten lost.

TL;DR

Overlap may be helpful if you need to share digital files with clients.