Despite a common slight misconception, Iceheart does not invent the Treacle Shield, but learns it from some obscure set of old carrips. (Anyone reading the source would find the attribution in meticulous, evil detail.)
The Treacle Shield is very resistant to anything approaching it from a perpendicular angle. Missiles and similar aimed directly at the user are slowed more or less to a halt. Anything coming in at even a slight angle has only the perpendicular component of its velocity stopped, resulting in it veering off to one side. Treacle Shield is visible when deflecting (and slightly visible all the time it's on), as a brownish almost-transparent sphere. It was named for the "sticky" effect it has.
The newer version is also virtually transparent, but more of a whitish-blue. It is informally called - by people other than Iceheart, and quietly - Bonbon Shield, because it can resemble a sugar shell. Its maker is thought to refer to it as an Eekle Shield, which is apparently a despicable pun in Soprone.