tips on good plain square hatch

Hi
Any one have tips or pics on good plain square hatch...no curves...just flat
Any one have tips or pics on good plain square hatch...no curves...just flat
or t n ttt for short (tnttt.com)
https://www.tnttt.com/
dales133 wrote:I used 1/8 gap to the bottom and 3/8 each side and top.
Id be using a wide T moulding around the edge perhaps