How do I make double-line horizontal table borders in Google Docs?

Question

I want to get a double-lined horizontal border for my table in Docs, like Word has. How do I do it?

Answer 1

Although this is currently not an option (as of May 4th, 2020), I found an ingenious hack to do it, and I created a webapps SE account just to share this.

First make a table. Then duplicate it below, so that both tables are aligned. It should look like this:

Then click on that empty line between the two tables, and click line spacing in the main toolbar:

Select Custom Spacing and you'll get a popup. Change the Line spacing attribute to 0.06 (the minimum allowed currently) and the Before and After paragraph spacings to 0, and click Apply.

And you'll get a beautifully double-lined horizontal border for your table! :)