ImageGear for Silverlight does not support setting the default value of a capability, but ImageGear .NET does.
In ImageGear .NET, for a capability that can be negotiated with a range container, the default value can be gotten or set using the ImGearCapRange.DefaultValue property. In ImageGear for Silverlight, the default value can only be gotten with the ImGearCapRange.DefaultValue property; this property is read-only.
In ImageGear .NET, for a capability that can be negotiated with an enumeration container, the default value can be gotten or set using the ImGearCapEnumeration.DefaultValueIndex property. In ImageGear for Silverlight, the default value can only be gotten with the ImGearCapRange.DefaultValue property; this property is read-only.