It's iron_bars, but better..

because of its Compatability with each other and it's great compitability, while still being different...

Its the perfect choice as a builder, because of the wider range and aesthetic spicing up the builds key aspect to be recognizable and clean.

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To get the variants, simply rename the files in ... \.minecraft\resourcepacks\Bars v1.0 TAC\assets\minecraft\textures\block  like this:

The one, you decide to use, should be named just iron_bars

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