Double external strokes: is it that behaviour right?

[Carlo Brovelli]

Just for making some practice I made this soccer logo about a fantasy team called Arena calcio with the shape of an ancient roman anphitheatre and text.

So, making the background shield or better the shape conteining the logo and types, i set a yellow fill with two external strokes, first yellow of 20 px and second blue of  21 px.

BUT the result is un-expected: I can see the "Scudo" trace with a minuscule Blue stroke

It's like as a little portion of the second Blue external exceed under the right side of the first yellow stroke.

I solved this issue playing with other combinations of stroke options BUT I would like to understand to fix this problem.

Here the file: https://assets.adobe.com/id/urn:aaid:sc:US:8a64fefb-5d78-408e-b872-9be78557a2de?view=difile

Many Thanks

[Met1]

"I can see the "Scudo" trace with a minuscule Blue stroke"

Yeah, 1pt...

Look in Apperance you'll see the strokes are stacked, it's not a stroke outside of a stroke, it's two strokes originating at the same place. If you want a 21pt stroke, make it 41pt...

[SJRiegel · Accepted solution]

another option is to use the Offset Path effect to move the stroke outward

[Carlo Brovelli]

Great solution @SJRiegel ,

adding a 40 px Offset Path the inner little Blue border disappeared 

and than adding a thin Blue external the target is reached!

Thank you very much 

[Carlo Brovelli]

Hi Met,

a misunderstanding occured.

I'm not talking about the just one pixel Blue external border: that is right what i want,

I'm talking about the subtle line around shown in the picture attached:

[Carlo Brovelli]

Hi @Met1 ,

as you see I leaved you an answer without tagging you.

Cheers

[Anna Lander]

This hairline appears because two strokes are placed on each other with the same position, it's not a very good composition. There are some ways to solve the problem. For example, you can set the yellow (top) stroke as Centered and 40 px width like Met1 says. But I would try to remove all strokes, add a new blue fill, put it under the main yellow one, and add to them the Offset Path effect. Set the yellow offset as 20 px and the blue one as 21 px, and make sure that the Transform panel changes the strokes and effects. Without the strokes you will not get the stroke artifacts.

[Carlo Brovelli]

Thank you @Anna Lander  for your tips!