Changing the appearance of glass blocks/panes

I think it would be really cool if we had the option to customise the appearance of glass blocks and panes similarly to customising banners. This would give you the option to add custom designs to your glass such as adding bars across the glass etc. This would work by placing a glass pane/block (dyed or not) to a table similar to the loom and simply choosing the design you want. This is especially great for adding extra touches to your builds and giving you the option to have more custom content without the use of texture packs.