I heard this somewhere, but alas, I don't know where. I just love the idea so I want to pass it along here as well.
I have always had a difficult time making knots or bows on my projects. They were too bulky, I didn't have enough ribbon to make a bow, I warped the project getting enough ribbon to tie, the knot or bow was not where I wanted it. In short I tried to avoid using tied ribbon if at all possible. Then, I discovered this and I can now put ribbon on any project and have a perfect bow or knot.
The first step is to adhere the ribbon to the project. I will adhere mine at the ends just in case I want to move something. I will then place another piece of the same ribbon where I want it tied.
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After that I tie the knot or make the bow. I make sure that the ribbon I am working with is long enough to make the size bow or knot that I want. The great part about this is that if the placing is not exactly where I want it, I can just slide the knot up or down to where I want it to be.
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And here is a sample of the ribbon tied onto a card