The complete guide
Buying magnetic strip by the metre
What you actually get for a metre
Both strips.
A magnetic window screen needs two mating halves: one secured to the window frame, and a self-adhesive one on the screen side. When you order a metre here, you get a metre of each. That is worth stating plainly, because it is what people assume and not always what they get.
Why anyone buys strip on its own
Three reasons, and they cover almost every order.
The first is building a screen for an opening that no stock size covers. Buy PVC frame by the metre, a corner piece set, a sheet of mesh and this strip, and you can screen any shape of window.
The second is splitting. One large magnetic screen cut down makes two or three small ones, which is usually the cheapest way to do a whole house, and each new panel needs its own run of strip.
The third is repair. A magnetic screen that has stopped sitting flush is almost never a failed screen. It is tired or dirty strip, and a few metres fixes it for a fraction of a replacement.
How much to order
Measure around the perimeter of the opening. Add a little for cutting waste and for the corners, because corners eat more than you expect.
Then order that many metres. An offcut in a drawer is a much better outcome than being half a metre short with the old screen already off the window.
Fitting it
It cuts with ordinary scissors. Nothing is drilled and no tools are needed.
The one thing that decides whether it holds is the frame. Clean off dust and grease, finish with an alcohol wipe, and let it dry, because the adhesive gets a single attempt. Work at 18 degrees or warmer in dry air, and if the room is cold, run a hair dryer over the frame first.
Press it down along its whole length and pay particular attention to the corners, which is where an under-pressed strip lifts first.
Living with it
It comes away from the frame without leaving a mark, which is the reason a magnetic screen works in a rented flat at all.
Wipe the strip if it collects dust. Grit in a magnetic seam is the usual reason a screen stops seating flush, and it is a thirty second job rather than a purchase.