Originally posted by scale buff
Excuse me, folks, but I've been using Monokote for 28 years and I have yet to see a grain in the material. It is milar and, to the best of my knowledge, has no grain. You can put it on any direction with the same results.
I have a model at home that demonstrates the difference in shrink very clearly. I covered the bottom of the wing with the monocote grain running with the chord and the sag between the ribs is MUCH greater than it is on the top of the wing. The top is fairly smooth. As smooth as you could expect from an open bay wing. The bottom sags at least twice as much as the top and the only thing I did different was to cut the the bottom panels from the roll with the length of the roll running with the chord of the wing.
If you don't cut your control surface panels from the roll lengthwise, you will also run into more issues with the covering lossening up when you set the model out in the sun.
John