Hello,
We only have 14ct. Platinum Aida available in a 15 x 18 cut and here is the link for it:
http://www.everythingcrossstitch.com/gold-standard-14-count-15-x-18-box-mrp-p41968.aspx
This is the only we can get this color from our distributor. Thanks!
~Kristi @ ECS