On 27 April 2015 Sikth announced via their Facebook page that they are planning to release new music in the form of a crowd funded EP with a tour to follow. Fans who pre-ordered the EP were able to visit the pledgemusic page and gain access to exclusive updates, content and merchandise for the duration of the funding campaign. The six track EP, titled Opacities, was released on 4 December 2015. Sikth were also the opening act for Slipknot on their 2016 U.K tour in February alongside Suicidal Tendencies. They were announced to be performing the Arctangent Festival in August 2016, but later pulled out. They appeared in 2017.