Biffy Clyro are sending fans postcards with a link to a mysterious site

Having updated their social media pages with a blank cyan header and picture, Biffy Clyro seem to be hinting at their return.

The band took their teasing tactics to a new level by sending out postcards styled like a panatone paint chip, with the same colour as their social media headers and pictures.

Biffy Clyro's postcards also included the colour code for the cyan colour - 2197 C - as well as a link to a mysterious site which shows an image of a handwritten note that reads: "Dear God, Adjust my dreams for me. All I learned is Instant History."

The hashtag "#THISISTHESOUNDTHATWEMAKE" is also featured on the page linked from the postcard.

One fan theory suggest that 2197 is 13³ (cubed), which could hint that a potential release date for their new album - 13 March.

So apparently 2197 is 13 cubed (13^3). Could this mean new music on 13th March???? @BiffyClyro #instanthistory #thisisthesoundthatwemake pic.twitter.com/GeXcDLRkdb

— Emma Goodchild (@EmmaG_94) February 14, 2020

Got a mysterious @BiffyClyro message in the mail...what does it mean? pic.twitter.com/naF4FbCUHJ

— Draven_RNF (@kaylubdraven) February 13, 2020

Me ha llegado esto de @BiffyClyro ... ¿Sabes algo @AlvaroBenitoV ? pic.twitter.com/CW4qRFzYl4

— JesúsGallego (@JGALLEGOonfire) February 12, 2020

The band are yet to confirm details of their follow up to 2016's Ellipsis. In October 2019, Biffy Clyro revealed they were planning to release the new album in the first half of 2020.

Although they haven't released a new album since 2016, Biffy Clyro haven't exactly been quiet - they released their Balance, Not Symmetry film score last year, and contributed a cover of Frightened Rabbit's "The Modern Leper" to their Tiny Changes - A Celebration of The Midnight Organ Fight album.