My mistake is very noticeable in the fire engine pillowcase I just made for my son is law. When you lean the pillow against the headboard of the bed, the fire engines are taking a nose dive into the mattress or driving up to the ceiling. I concentrated so hard on keeping the wheels oriented down toward the contrasting fire hose border that I did not realize I was off by 90° and the fire engines were sideways. Somewhat in my defense (in other words, my excuse), the instructions stated that if you have a directional print be sure it "stands" on the contrast band. The instructions called for three quarters yard of feature fabric but did not mention more was required if the fabric were directional. Come to think of it, the instructions, which I have used many times, originally came from a pillow case kit. The fabric had been pre-selected and was non-directional.
The main body of the pillowcase is sewn from a 27" x 41" piece of fabric. The 27" is the length of the pillowcase and the 41" is the folded-over width. In most cases, for non-directional fabric, it would make sense to use the fabric width for the 41" dimension and three quarters of a yard for the 27" dimension. For most fabrics with a directional print, the up and down direction of the print generally runs parallel to the selvages of the fabric along the length of grain. If you get that 27" from the three quarter yard length direction, the images are sideways when the pillow sits on the bed. For fabrics with an up and down direction of the print parallel to the selvages, like this fire engine print, even though it is the norm for a directional fabric, you need one and a quarter yards of the feature fabric per pillowcase in order to get your 41" dimension.
This did not became obvious to me until I began to make a pair of Christmas pillowcases out of Christmas fabric where the up and down direction of the print runs cross grain. This directionality is not generally the norm but can be found in banded stripe fabrics from a fabric collection. I thought, aha, directional fabric, I will need more. Actually, no, because the up and down direction of the pale fabric on the right runs cross grain I still need only three quarters yard.
The darker grey fabric on the left has an up and down direction that runs lengthwise with the grain (generally the norm). I used it just for the border. The contrast border is cut 10" x 41". Since it drops over the edge of the mattress anyway I felt the 41" could come from the fabric width and would be pretty wasteful if cut along the length. I did need to fuss with the orientation though so the border did not drop over the edge of the mattress upside down.
I also fussed and considered if I wanted the band to have stocking and doves or snowmen and trees. But that is another sort of fussiness and irrelevant here. Here is one finished pillowcase and I have one to go.
Since I am making a pair of pillowcases I realized another aspect to consider. The two pillowcases would have a right or left handedness to them so that when the print of the main body was oriented correctly for the bed, one would open to the left and one would open to the right.
It took me longer to describe this than to figure it out. Hopefully it was arduous enough that I will remember it next time I decide to "whip up a pillow case" or buy that cute novelty print because "I only need three quarters of a yard for a pillowcase".
So in summary:
Up-down fabric direction is along length of grain? Get one and one quarter yards.
Up-down fabric direction is cross of grain? Three quarters yard will do.
Contrast band is directional? Be sure it will drape over mattress edge right side up.
Making a pair? Take care that one opens to left and one opens to right.
I am off now to check out other folks creations at WIP Wednesday at http://www.freshlypieced.com/
Stats since last WIP 9/18/13:
Completed projects - 1 pillowcase + helped daughter in Oklahoma move
New projects - 1 pillowcase + recovering from helping daughter move