Big Shot Multi-purpose platform with both tabs.
4 A4 sheets of cardstock folded in half.
An A5 or A6 greetings card blank
An A5 or A6 Universal Magnetic Aperture Mat.
Nestabilities die of your choice
Big Shot Cutting Mat
Big Shot Apurture Sandwich from bottom up.
Start with your multi-purpose platform with both tabs over the top of it.
Now stack your four sheets of folded A4 cardstock on top of the multi purpose platform (this will be your shim)
Next place your nestabilitie die (cutting edge up) onto the magnetic aperture mat and slide this in between your greetings card blank and place this on top of your shim.
Finish by placing the Big Shot Cutting Mat on top of your sandwich and it is all now ready to go through your Big Shot Machine.
And Voila you have made your own aperture card.