Subtle line appearing between overlapping shapes

Using Sketch Version 100 (180108) on Mac.

I’m working on making a repeating pattern. I have two tiles which are color inversions of each other that I want to repeat. The problem I’m running into is that the SVG is exported with a subtle line between the tiles, which somewhat ruins the effect.

Here are the tiles:
CleanShot 2024-07-05 at 16.15.22

And here’s the seam that appears.

I seem to have solved it for the seam between the left and right tiles by not using the snap-to feature and instead giving them a tiny overlap, but that isn’t working for the seam between the top and bottom tiles.

How do I get rid of this?


Hi there! :wave:
Could you upload a Sketch file with the patterns in it, and we can take a look at it for you.
Thanks. :pray:

Here you are
Box Pattern .sketch (571.6 KB)

Hi there. Thanks for sending that document through.
When I look closely at it, I can see that certain parts of the tile are not sitting on the edges of the Artboard, and they are also positioned on non-whole number co-ordinates.


When I take these tile patterns and make each one a perfectly square Symbol, and then place these Symbol Instances onto a whole-number pixel grid with no gaps between them, then the seams disappear.

I’ve attached the edited document here.

BoxPattern.sketch (124.0 KB)

It’s worth noting though that at certain view sizes / magnifications in the edit environment, you might still see a seam on your document, but rest assured, if set up correctly, they will not appear in any exports.