DSU sells lengths of PVC refrigerator profiles with magnet. A fridge seal can be put together by cutting the corners in 45 degree angles and gluing them together. This method is seldom used nowadays.
Ordering a bespoke fridge door seal with welded corners is preferred over glued corners. Welded corners are stronger and it makes the seal more durable. Ordering a bespoke fridge seal also saves a lot of time when installing the seal compared to having to cut the profiles at the correct measurements and gluing the corners together in a 90-degree angle.