I am creating a set of comic strips. I create each panel in its own Illustrator file. Then, when it's time to assemble the panels into one strip, I copy, paste, and shrink the images so that multiple panels are on one page. Some of these panels have a Gaussian blur. When I do the rescaling when assembling the comic strip, the blur looks not like a blur but pixelated. Is there any way around this?
Do you have the same resolution in Document Raster Effects Settings? Sounds like you could have lower resolution in the document you paste in to. Try change that in that case.
Go to Effects > Document Raster Effects Settings and change the resolution to 300 ppi (or whatever default resolution you prefer)
If your final image is really tiny then it will look like pixels... You need a larger image to get higher quality, there's no way around it.
If you have a 300 x 300px image and you shrink it to 64 x 64px, it will look pixelated. There are not enough pixels to contain the same amount of detail as the larger version.