What you Need to Know About the Screening Spline

 This flexible cord, known as a screening spline, plays a crucial role in installing window screens.

A screening spline securely holds a window’s screen in place when rolled into the channel or groove of the screen frame.

It keeps the screen fabric taut into the screen frame and prevents it from moving. Spline is available in either black or gray. Black is typically used with charcoal fiberglass and aluminum windows. Gray goes with gray fiberglass and bright aluminum. Screening splines come in different diameters since there are different groove widths and screen frames. To ensure that you get the correct spline size for your existing frame, you can use a sample of your older spline to compare.

Screening spline is made from different materials. These include EPDM, a kind of hard rubber, and hollow core vinyl which can be stretched as you roll it in, making it easier to work with even if the diameter is a little too big for the frame. Many still prefer the polyfoam spline as it is more flexible. It is the best option for beginner since it is easier to roll in and can be used in a wider variety of screen frames.

A foam screening spline can be compressed so that a larger diameter cord can be used in different situations. Another style of spline is the “T-spline”, which is used in ultra-thin frames of aluminum storm doors. Its cross section is shaped like a letter “T”, as the name suggests. It locks the material in place more securely than regular polyfoam spline does. However, you’ll need to have the exact size because otherwise it will not work properly.

Spline comes in rolls that look the same as electrical wire, usually available in sizes measured in decimals of an inch.

At Alcot Plastics, we also offer custom-made splines to best suit any of your window or door measurements. Visit or call us today to find out more!