Originally Posted By: tc1446
Looks like synthetic filter.
Its not a "synthetic" filter.
That's a Champ Labs ecore filter. Its got a plastic center-support tube, regular cellulose media (standard type), and then they sonic-weld the poly end discs to the media. I'm guessing they have a media with some type of poly in it (polyester?), at least enough of it to bond the poly discs to.
Champs ecore bonds plastic to plastic. FRAM bonds paper to paper. Both are generally easier to achieve than bonding steel caps to paper (easier to bond like-materials). Mann uses this resin-looking stuff in both clear and yellow opaque. A better bond means a better seal, and, less likely for the glue to flake off into your engine.
Cheers.