We cannot print extremely intricate vector objects. This happens most commonly with arcitectural drawings. There are many ways to rasterize but the following are a couple of techniques.

Click the Effects menu in the top horizontal toolbar, after you have selected your objects. Select "Rasterize" from the Effects options. Select the Rasterization options, exactly as you would if you were permanently rasterizing an object. Go to the Appearance panel to modify or delete the effect.

You can simply bring the document into photoshop at 300dpi and it'll give you a more predictable way that we'll reproduce the file.

before at 800%