Stop Sketch adding extra pixels around a slice?

Question

This is my first project working with a sketch file (given to me by a designer for me to cut up into HTML/CSS).

So far I've loved the way sketch makes exporting easy, but I'm running into some trouble here. I have a slice drawn around a couple of vector layers that form a mask over an image. I have the slice perfectly clipped to the edges of the layers, but in the preview panel (and also when I export) sketch is adding pixels around the edges.

The "Trim transparent pixels" checkbox does nothing. What should I check next? Or am I doing it all wrong?

Answer 1

Your callout-bg-mask seem to have a box shadow. The slice may be a child of this layer, it still inheritates the shadow and this may cause the slice bug ; try to disable it before exporting the slice.

I tried this and have the same problem :

Parent has a shadow :

Parent has no shadow :

Answer 2

Try and export first and see if it adds the pixel around it, I think it's just for show. Temporary fix is to open in Photoshop, cmd select the layer then crop the pixels.

Answer 3

I found a work around to this: add an artboard the size of the slice, then paste your asset into the artboard. When you export, it should be the correct size.