While I don't feed my Kleenex box to my worms it does have the recycle emblem on it. I normally just try to tear things - if they tear I will compost them but that is a diff pile.

http://www.genpak.com/images/green-room/boxes/recycling.png

The shiny coating on some thin cardboard, like cereal boxes, tissue boxes, etc. isn't harmful to worms, but it makes the cardboard less able to absorb water, even after shredding. I have so much other cardboard I can use that I don't generally use that type of cardboard. Some food box cardboard has a non-shiny surface (especially on the kind of earthy-crunchy food I tend to buy) and I'm more inclined to shred that cardboard up for worm bedding.

Jack, in thinking about this you might try soaking these Kleenex boxes to soften them up then mixing with some other worm food that is beginning to decompose. Or put them thru a shredder and use them for bedding or whatever.

It might be worthwhile to shred it as small as possible and see what happens in the end[harvest time].

The shiny material is a plastic film. You can peel it off carefully after soaking the material in hot water and wringing it, but I am not sure that it's worth the effort.

Sometimes it's a clay coating and sometimes it's an actual plastic film. Hard to know which, until you are picking the bits of plastic out of your vermicompost.

I learned the hard way that paper sweetener packets have a thin plastic lining in them, which you wouldn't know is there, because the outside of the packet just seems like porous paper. I was throwing the empty packets in with my worm scraps for a while, and now I'm picking out all the liners. Sigh.

<paper sweetener packets have a thin plastic lining in them, which you
wouldn't know is there, because the outside of the packet just seems
like porous paper.>

Exactly why I use the "tear technique" I mentioned above. You should be able to detect any artificial material when you tear or rip something.

And yet I tear those little packets open every morning before I've had coffee! Truly, they tear just like paper. Try it yourself.

NO Sugar for me, I am sweet enuff :-)

fwiw - I just noticed that cereal boxes have the same type of finish found on the Kleenex boxes, except w/o the plastic. I sent mine out to the pile.