After catching a Home Improvement show on T.V. I discovered what went wrong: When using this tape you must remove it as soon as you finish painting the area (while the paint is still wet). You must also use caution and brush from the tape to the wall, not the wall to the tape. If you brush upwards toward the tape, some paint will leak through underneath.
It would have been very helpful to know this BEFORE I used this product.
If used properly, this product does work; however, if you do not know its secrets....look out.
Any questions, please let me know in the comments.
Happy painting!