The project uses the fairisle and intarsia techniques on the tiles section of the cushion, the back and picture frame sides are in striped stocking stitch. 
The yarn I used is Rowan Felted tweed in 4 shades. 1 50g ball of each.
This cushion has an approximate finished measurement of 39cm x 39cm.
 
This design is also available as a kit which includes yarn used and the printed pattern. 
https://www.lisarichardson.co.uk/product-page/mitred-cushion
Other shades are available so please do ask.
 
The pdf download will be emailed to you.