In the art of tear shades, flexible shade material (usually thin polyvinyl chloride) is wound onto a shade roller which is equipped in one of various possible ways to telescope within itself to shorten its length. The shade material is scored from top to bottom of the shade along one margin with spaced parallel score lines usually 1/2" apart. When a width adjustment is desired, the user starts the material tearing along a selected score line, peels off the unwanted part, adjusts the length of the shade roller, and then mounts the adjusted shade in place.
The problem encountered in many arrangements is that the material tends not to start tearing accurately along a selected score line. It will be understood that the score lines must not be so deep that the shade material will tear easily otherwise there will be a risk that they may tear accidentally in use. For this reason it is preferable to have score lines which are on the shallow side, i.e. only sufficiently deep to provide uniform and accurate tearing. With such tear lines, however, the start of the tear becomes a problem.
In one form of tear shade a v-cut is formed along the bottom edge of the shade with the apex of the v on the tear line. This form has several drawbacks. First, starting the tear is so easy that there is a substantial risk of accidental tearing. Second, the apex of the v must be vey accurately positioned or else a tear will be started elsewhere than on the desired tear line.
Accordingly, an object of the present invention is to provide convenient, sure means for starting the tear, in a tear shade along a selected score line.