When you drop any coloured glass and glass panes in front of some items, they become invisible. Those items include: iron bars, ladders, scaffolding, all saplings, all planted seeds (including carrots and potatoes), sweet berries, fern and large fern, grass and tall grass, coral, all flowers, vines, dead bushes, bamboo, sugarcane, cobweb, monster spawner, all types of glass (including glass panes), Nether wart, lanterns, campfires, all beds, torches, brewing stands, anvils, co posters, water, lilly pads, flower pots, heads, dragon heads, bells, beacons, conduits, stonecutters, end crystals, all boats, red stone torches, all rails, all minecarts, redstone, levers, tripwire hooks, repeaters, comparators, hoppers, the wooden part of pistons and sticky pistons, all banners.