How to use tissue paper as stabilizer

I’m sure you probably already know about the trick of using tissue paper to aid in sewing delicate and/or fluid fabric. Sandwiching the fabric between two strips of tissue paper prior to stitching adds stability, preventing the feed dogs and the press foot from distorting the fabric as it’s being stitched. The tissue strips are torn off after stitching. I use tissue paper scraps from commercial patterns, cut into strips of about 1″ to 1 1/4″ wide. I cut the strips freehand using with a rotary cutter.

The trick I’m detailing today is how to orient the tissue when cutting it so that it’d be easier to tear off after stitching. Commercial paper is almost guaranteed to have grain direction, just like woven fabric. The fibers in a sheet of paper are parallel to each other and oriented in one direction. The grain almost always run parallel to one edge of a sheet or strip of paper. This is true for sheets of paper as well as paper on a roll such as toilet paper, paper towel, examining table paper, etc.

Fibers of sheets of paper almost always run in the lengthwise direction. Fibers of paper on a roll run lengthwise. My conjecture is that this is because the paper is tensilely stronger along the direction of the fiber, which makes the manufacturing process easier, the paper being less likely to tear when pulled in the direction of the grain.

The way to find the direction of the fibers is to tear the paper. When torn parallel to the grain, you will find it quite easy to tear long continuous strips with fairly straight edges:
tissue paper torn with the grain

When torn across the grain, it’d be almost impossible to tear in a straight line:
tissue paper torn across the grain

Once you find the grain of the tissue paper, cut the strips so that the grain runs lengthwise. Since paper is tensilely weaker across the grain, it’ll be much easier to tear the strips off when the grain runs parallel to the stitching line than when the grain runs perpendicular to it:

Here is an example of using tissue paper in a pseudo-flat felled seam. I first stitch the seam, then tear off the tissue paper on one side, press the seam to that side, then add another strip of tissue paper on the right side with its edge right on the seam’s fold, pin, then stitch and tear:
flat felled seam in lace with tissue paper, step 1 flat felled seam in lace with tissue paper, step 2 flat felled seam in lace with tissue paper, step 3

As an aside, it’s not practical to use zig zag stitch when using tissue paper as stabilizer. A straight stitch creates a straight line of perforation so that tearing the tissue paper off would be simply “tear along the dotted line”. There is no one line of perforation with a zig zag stitch and that makes tearing the tissue paper off more difficult:
tissue paper does not work well to stabilize a zig zagged seam