A brass arm means the light can be angled specifically towards artwork and adjusted as the angle of the sun changes throughout the day. Brass as a material develops patina which adds character and warmth to the installation. The adjustable feature is genuinely practical because different artworks need different light angles and the flexibility means one light can work for multiple pieces as you rotate your collection. The arm construction should be substantial enough that the light stays where you position it rather than drooping. Most quality brass picture lights have a weight and substance that signals they are meant to last and earn their place on your wall. The warmth of brass complements artwork across styles from contemporary to traditional without the institutional feel of chrome or steel. These are the picture lights that do the job properly by letting you control exactly where the light falls on the piece you are illuminating.