It has happened to me several times that I totally ruin a layout when trying to frame it with stitching using my Sew Easy tool. My lines NEVER come out straight as I wish and exactly in the place I want they to be, so after a lot of errors and paper lost I came up with this idea.
First you will need to place the paper you want to stitch over the piercing mat and then place a ruler over the paper.
Once you have the paper and the ruler perfectly aligned, start piercing carefully with the Sew Easy tool. You may need to make few tries until getting a perfectly straight line.
Once you are done you will get something like this, nothing new until now, uh? Now you will see the trick ;)
Trim the paper as close to the pierced line as possible, first on one side and the on the other side.
Once you've trimmed the paper you will have a band like this.
Place this pierced band over the place you want to put the stitching on your layout and start piercing the paper. This way you will be sure that the line you are piercing is perfectly straight and you wont ruin your project by improvising a line ;)
And there you have it, a completely straight line! Hope this trick will be useful for you, thanks for your visit!