Originally Posted by HomerSimpson

There are some silicone gels/glues that you can buy in some stores (some puzzles come with it), that you just mix with water and then apply it on it.
since it's silicone gel it keeps it together and it's pretty elastic, it's also transparent and itis applied over the picture. It keeps the things lot easier once you put it all together...

I personally admire people who have patience for something like that, since I would throw those pieces out the window the second minute...