enchanting armor changes render method in weird way.

I am currently working on a texture pack (hear me out) which makes armor see-through to appreciate skins more. I didn't want to make it fully invisible though because people using the pack would have disadvantages on servers.

Then however, I noticed that when the armor was enchanted, The Chestplate remained see-through, and the rest became solid. When removing the Chestplate, only the Leggings were see-through. When removing those the Boots. After that the helmet.

The pack changed nothing except for the opacity of the armor.

I know this could be seen as modified content, but it is a big restraint for texture pack makers, and I didn't know where else I could report this.