Tartan kilt and/or a piece of tartan material (Weybridge KT13)

My 11 year old grandson is playing the part of Macbeth in his end of year school play. The school are asking that he be dressed in a tartan kilt and wear a tartan sash. Does anybody have a tartan kilt and/or a piece of tartan material big enough to make a sash for him? Thank you for reading this.