The Grand Arctek Torch is a light-source that you can craft yourself (in your Crafting Menu, default key "Q", or at any old Crafting Table in in worlds created before R22 on September 16th 2015) after unlocking it by taking/crafting an Arctek Torch for the first time (for example as a rare finding in Diamond Treasure Chests or loot/harvest from the Thing). To craft 8 Grand Arctek Torches at a time, you'll need (as of R22 in September 2015): Mind that you can make 8 Grand Arctek Torches from 4 Arcstones compared to all other Arctec light-sources (only 4 units at once).