+ vertical/horizontal lines. In general the bottom and right sides of
+ the video will not be bordered by the grid. So for example, if you
+ only add the effect to the video, there will be a frame around the
+ video with the size of the \textit{thickness}
+ but the frame is only visible on the top and left and not on the bottom
+ or left side. You can get a line to show by using a larger thickness
+ and specifying a negative value for x and y of -2, -3, or more.