Laybacking requires the crack to be off-set (i.e. one side protrudes) or in a corner, to create the opposing forces needed for the technique.
[1] The friction needed for 'jamming' can wear the climber's skin, requiring medical tape or specialist gloves for long crack routes.
[2] The invention of spring-loaded camming devices in the 1970s revolutionised the difficulty of cracks that could be attempted by traditional climbers,[2] and led to new grade milestones set on crack-routes such as The Phoenix in 1977, the world's first-ever 7c+ (5.13a), and Grand Illusion in 1979, the world's first-ever 8a (5.13b).
Swiss climber Didier Berthod 'greenpointed' the bolted crack line of Greenspit at 8b+ (5.14a),[8][9] as did Canadian Sonnie Trotter on The Path,[10] and Austrian Beat Kammerlander [de] on Prinzip Hoffnung.
[11] In 2006, new traditional-grade milestones were set on crack-climbs by Trotter on Cobra Crack at 8c (5.14b),[10] and by Scottish climber Dave MacLeod on Rhapsody at 8c+ (5.14c).