Blujewel,
Welcome to our forum.
Corian sheet size is 3680mm x 760mm
Avonite Antique Glass is part of their Studio Collection and is available in sheets 915mm x 3050mm long.
From the outset here it's important to note that the Avonite Studio collection is not aimed at residential applications and given the finish is transluscent, adhesives, cabinet supports and such the like would be visible through the surface.
The Avonite Studio Collection from which Antique glass is offered, is a Polyester Solid Surface as opposed to Corian's predominantly Acrylic make up. It's also imporatnt to note here that, although we offer Corian to our visitors, Avonite also offer a range of Acrylic surfaces and have enjoyed a longstanding reputation as a leading Solid Surface provider.
To differentiate polyester and acrylic solid surfaces, acrylics can be thermoformed to the tightest of radiuses where polyesters cannot and both products are less resistant to heat than a quartz surface would be.
Fabication of Avonite Glass surfaces places greater demand, time and material cost on the fabricator so it's no surprise that costs are higher than that of a Corian kitchen surface colour unless of course your choice is for one of the Corian Illumination series of colours, in which case fabrication costs may prove similarly elevated.
See the following post for more information on this -
http://kitchensfitted.co.uk/KitchenForum/viewtopic.php?t=615As for Avonite polyesters being more brittle this is true and Acrylic has a number of advantages over polyester in that it's harder, has a greater resistance to impact and is less brittle. Acrylics also have a greater resistance to UV light.
My advice would be to consider one of the 72 colours of Corian that are recommended for kitchen worktops unless you are fully aware of the greater cost implications and potential issues that might arise out of choosing a surface that is not recommended for the heavy use it would be subjected to in a kitchen.