'Framed' - Tensioning the Light Lines

This was possibly the scariest thing I've done in a while !
It's not every day you take to your own embroidery with a staple gun, risking wonkiness & ruin !!*
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. . . but then it's not every day you really need to know whether or not what you've decide to do will work.
& even tho the 1st one worked I still procrastinated about doing the 2nd one simply because I was worried that the 1st one had somehow only worked by sheer good luck . . . 
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. . . turns out the 2nd one worked too.

There were 3 things I was evaluating.
Would I be able to evenly tension the fabric to get the lines lying taut, could i get 'nice' corners & which thickness frame would I prefer for this series

I am happy to report that the answer to the 2 technical questions is yes & yes
. . . I am undecided about which thickness I prefer.

*nb i come from a long line of drama queens hence the need for multiple exclamation points