Cosplayers, take note. For maximum realism, scratch up your costume with sandpaper.
In the Game Of Thrones' costume ageing department, a team of 10 artists take items fresh from the sewing machines - the leathers worn by the wildlings, the woollen coats of the northerners, the vests of the Dothraki - and apply scrapers and abrasives to them so they look like outfits people actually wear day in and day out.
That lived-in look is especially crucial for the army of the undead, the wights. The clothes range in age from the seasoned (for the newly deceased) to tattered clumps for those resurrected after a long stay in the ground.
Here at Titanic Studios, five minutes from central Belfast, Northern Ireland, is the Game Of Thrones production headquarters.
In its vast 140,000 sq ft space are the soundstages where scenes at the Wall are shot. There are also various rooms of the Red Keep, including the Iron Throne room and Daenerys Targaryen's throne room in Meereen. Here is also where the infamous Red Wedding scene was shot.
The marble interiors are mostly veneered boards, but the carved wooden furniture seen in palaces are real and by on-site carpenters.
Construction manager Tom Martin, 34, says there was an especially challenging request - build a version of the Wall that could be climbed with axes. The result can be seen in Season 3 in a perilous climb by Jon Snow, Ygritte and others in the wildling party.
Over the show's past five seasons, it has contributed an estimated £110 million (S$212 million) to Northern Ireland in spending on goods and services. That is not counting the tourism. Fans from all over the world come here to take one of the many Game Of Thrones tours that have sprung up - none of them, though, is authorised by the show's parent company, HBO.
The production hires about 6,000 extras every year to play wights, soldiers and the brotherhood of the Night's Watch. In the show's Emmy-winning costume department, their outfits are stored neatly in racks. They are never cleaned - "preserve the dirt" is the mantra here, for realism. To stop the wools, linens and leathers from smelling, they are given a spritz of alcohol now and then.
Mr Steven Murphy, 34, is an armourer and blacksmith here. The show's iconic weapons - Arya's sword Needle, the Stark sword Ice and Brienne of Tarth's blade Oathkeeper - are made by the studio's armoury. The weapons are made of steel when possible, but sometimes plastic and rubber are used, for example in the translucent swords wielded by the White Walkers.
All the crossbows seen in the show work, says Mr Murphy, including the one that ends the life of Tywin Lannister (Charles Dance).
Asked which sword he would use if he had to fight a knight, he replies: "I'd use an axe. A good axe would shatter a sword and cut through armour."