Cut right angled corners (or strips which can then be taped together at a right angle) from solid tag board or paper wide enough to visually block out the fabric extending beyond the area of focus (the area inside your frame). Mine are two inches wide (5 cm) and that’s probably the minimum width you can have to get a clear idea of your focus area. Notice that you do not need to cover all the fabric extending beyond the frame but just enough to make it easier to focus on what is inside the frame.
If you plan to use this tool again and again mark off the inches (or centimeters) down both legs of the corners so you can adjust the frame for different size projects with ease.
Good idea!
Thanks. I learned this in art class. We would cut squares or rectangles out of paper to focus on a particular area of a larger piece or hold it out in front of us to focus on a section of the landscape or the still life. Since I wasn’t sure what size (or shape) I wanted to cut from the fabric I wanted to make my “view finder” adjustable – that’s why the two right angles (that and it’s easier than cutting a hole out of paper).