Get rid of red bars in Sketch

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If you're slicing a design from a designer in Sketch, you may find some horizontal/vertical red bars. Here's a quick little how-to on how to get rid of them.

Go to the Sketch artboard with the red bars
Go to View in the top Sketch menu, in the dropdown, hover over Canvas and then Layout Settings
You'll see something like this:

Uncheck Columns and Rows, then press Confirm and hey presto, bars are gone!