Despite their advantages, early operable awnings had drawbacks; when retracted, their cloth coverings often bunched up against the building facade. This left part of the fabric exposed to inclement weather, and deterioration was often accelerated by moisture pooling in the folds of fabric. If poorly designed or badly placed, the retracted fabric could obscure part of the window or door opening, and even if out of the way an imperfectly folded awning presented an unkempt appearance. Modern materials and designs have eliminated all of these issues.
Modern awnings may be constructed with covers of various types of fabrics, aluminium, corrugated fibreglass, corrugated polycarbonate or other materials. High winds can cause damage to an extended awning, and newer designs incorporate a wind sensor for automatic retraction in certain conditions.
It also can be used to cover the thermal solar panels in the summer.
The other (projecting) end of the canvas was draped over or laced to a front bar with the edge often hanging down to form a valance. On ornate examples, metal posts were adorned with filigree and the tops decorated with spear ends, balls or other embellishments. On overcast days or when rain did not threaten, the covering was often rolled up against the building facade; during the winter months proper maintenance called for the removal and storage of awnings. Photographs from the mid-19th century often show the bare framework, suggesting that the covering was extended only when necessary. Canvas duck was the predominant awning fabric, a strong, closely woven cotton cloth used for centuries to make tents and sails.