On one of the longer sides place 4 eye lets near the edge
On the other side do the same but place the second strip 2" parallel
When I came across this he had used the hooks on the door frame and had left a 1' gap from the floor
Using the provided slot in the canvas  I shot my load and I still don't have a clue who it was but it wasn't just my spunk in a puddle dribbling under the gap. The glory hole was not there the next day but I will try same time next week.  Building was a deserted old shop.