Railing in Doom Builder question

[Ancient EviL]

So there are some textures in Doom that I'm unaware how to use properly, for example, there are certain textures that have gaps in them so you can see through them, but when i use these textures the gaps appear with black fill. I want to make a railing on a bridge in a map I'm working on, but again, the gaps of the railing are suppose to be see-through, but appear black. How do I fix this?

[scifista42]

You are supposed to use transparent textures only as middle textures on 2-sided linedefs. Not on 1-sided linedefs, and not as lower or upper textures on 2-sided ones.

[Ancient EviL]

That information is exactly what I needed, thank you very much!