Outdoor Fabric Central can provide real looking publications for estimating cloth yardage
https://local.yahoo.com/info-169556984-Outdoor-Fabric-Central%3Bp%3DOutdoor%2BFabric%2BCentral%26ei%3DUTF-8%26selectedId%3D169556984/
Outdoor Fabric Central provides practical guides for estimating fabric yardage and choosing the right weight for projects.