Scalloping Explained: Why Outdoor Blinds Don't Always Stay Perfectly Straight

What is Scalloping?

If you've ever noticed a slight curve or wave at the bottom edge of your outdoor blinds, you are looking at what the industry calls 'scalloping.' It is a common observation for homeowners across the Sunshine Coast, from the windy shores of Moffat Beach to the quiet, sunny streets of Buderim.

Many people worry that a scalloped edge means their blind is faulty or poorly made, but this is rarely the case. It is actually a normal characteristic of tensioned fabrics, particularly over wide spans.

Why Does Scalloping Happen?

Scalloping is primarily caused by natural forces and physics interacting with flexible materials. The most common factors include:

• Heat Expansion: As temperatures rise during a hot Queensland summer, the fabric and synthetic threads naturally soften and expand, causing a slight droop in the centre.
• Constant Tension: The weight of the heavy bottom bar pulling down constantly on the fabric causes the middle section to stretch slightly more than the edges, which are supported by the side channels.
• Over-tensioning: Cranking a manual blind down too tightly or forcing it past its natural stopping point puts undue stress on the fabric fibres.

How Fabric Choice Affects Scalloping

The type of material you select dictates how the blind will behave over time. Woven mesh fabrics like Vistaweave tend to scallop slightly differently than solid clear PVC due to their intertwined yarn structure.

At our Warana factory, we carefully cut, weld, and assemble all fabrics to exact tolerances to minimise initial scalloping. However, some minor movement and settling over time is completely expected and natural.

Best Practices to Minimise Scalloping

While you cannot defy the laws of physics, you can manage the tension on your blinds to keep them looking their best for years to come.

What to Expect Over Time

Over the first few months of installation, your new blinds will 'settle' into their environment. A minor amount of scalloping (usually a few millimetres to a centimetre over a wide drop) is perfectly normal and does not affect the performance, wind rating, or warranty of your Kawana Blinds product.