Ai. Art is blurry when scaled even when using continuous rasterize

Your AI artwork should be created at or close to the same size that it will be in your comp. Do this by making the AI artboard the same size as the comp. If you want Continuous Rasterization to work your AI layers cannot have any raster effects applied to the objects. If you want an accurate preview the Comp resolution should be set to Auto and the magnification factor should not be higher than 100% for normal displays or 200% for HR displays. AE knows the difference and will give you an option of Scale to Fit up to 200% if you have an HR display.

There's more than a 90% chance that this is user error. Screenshots and a detailed workflow description would help us help you.

Have you saved your files as .ai?

Impossible to know. You have not offered any details about your artwork, your system, your version of AE. and just to preempt this eternal misunderstanding: Just because it's doen in AI, doesn't mean it must be infinitely scalable vector artwork. AI uses pixel-based effects for drop shadows and so on just like any other program and specific stuff like blends, natural brushes, transparency blending stuff and so on can still cause flattening and data be stored as pixels, even if it's generated from vectors. Well, whatever. You have to be much more specific.

Mylenium