Traca, I found my British cookbooks use "almond paste" to cover a cake.
Not sure how you're planning on using it.
In the British recipes, it sounds like a marzipan that they're using, rather than the canned softer almond paste that is used for fillings, etc.
In particular, I'm referencing Peggy Porschen's Pretty Party Cakes. Her wedding cakes are covered with rolled "almond paste" to seal and provide a smooth surface, then that is covered with rolled fondant for the smoothest top surface.
You would need to add powdered sugar to most canned "almond paste" to roll it out.
I bought a 7 lb can of "almond paste" and was told I could just roll it out. But since it was for a test cake and it cost $36, I returned the can unopened. Can't give you any test data on that.