18 x 2 plastic gridded imperial clear ruler.
For professional quilters and sewing enthusiasts with more complex project measurement requirements, the Dritz Quilter's See-thru Drafting Ruler
Dritz 2 x 18 Quilter's See-Thru Drafting Ruler, Clear
This 3-1/2 inch x 18-1/2 rectangle ruler features easy-to-read black and white markings printed in 1 inch grids marked in 1/8 inch and 1/4 inch increments. Use the easy-to-read numbers and 1/4 inch grip side to cut whole inches and trim seam allowances. Use the patented Turn-A-Round feature and the 1/2 inch grip sides to add the 1/2 inch seam allowance. Use the white 45 degree angle to trim half-square triangles in whole inch increments.
Creative Grids Quilt Ruler 3-1/2in x 18-1/2in - CGR318
Quilting Ruler 3-1/2 x 18-1/2, Creative Grids : Sewing Parts Online
Quilters Select 2.5 x 18 Ruler - 844050013555
Omnigrip By Omnigrid Non-Slip Quilter's Ruler 2.5 x 18 - 20677675
Spirals Quilt Pattern Pillows Placemats Wallhanging Wall Quilt
Notions – Sewing Supply Depot
The 18 x 18 Quilters Select Non-Slip Ruler features a unique, non-slip coating on the back, so you don't have to fuss with your fabric or worry
Quilters Select 18 x 18 Non-Slip Ruler
Creative Grids 18 Degree Dresden Plate Quilt Ruler
Creative Grids Quilt Ruler 8-1/2in x 18-1/2in - 743285002030