... to build a blog without lines?
Theoretically, yes. While it seems impossible to build a blog without text, it is possible to build one without any lines on it. Yes, it might sound weird and didn't make sense to you, but maybe you should free your mind. Lately, I've been encouraging one of my friend to do so (making a blog without lines). In my opinion, a border in your blog doesn't have to be composed of lines. Your text can also designed to make a good border. For example, if you are reading this post, I am using justified-text-alignment. Even without the line-border, your mind (should) perceived the text as a box (isn't it? well, it should be hehe). And now, that my encouragement has succeed, you may want to see its result. Just click here for an example of it. It still doesn't look good since it is still under development every day, but should be enough for now.
p.s. that blog actually still has lines on the linked-text :) but for now this is as close as it can be to a lineless blog, isn't it?