Certain parameters are needed often when drawing, for example, the color in which to draw, the width of lines, the texture with which to fill areas. These are examples of what we call graphics attributes. In X, graphics attributes are associated with drawing procedures. Rather than mention the same attributes over and over again, ProXL applications handle these graphics parameters by associating a set of graphics attributes with each drawable, and changing them at any time. So if you want to draw a line of width 2, then another of width 5, your program would have to change the line width graphics attribute of the drawable. In fact, this is not necessary, as we show in pxl-bas-graf-gc.