Protective plastic on new waterblocks?

[Pessimisten]

Hi, don't know if this is the right place for asking this but here it goes, what's that plastic waterblocks manufactures uses to protect the underside of the blocks when they are new? Is it some type of tape or what is it? Where can you buy it?

And if no one knows the answers to my qusetions above, is there any material you can use to protect the underside that don't leave any residue on the copper?

[Psyche911]

I think I've heard people suggest just using saran-wrap...

[specialblend218]

I would just put 4-5 layers of masking tape on it since it doesn't leave any residue.

[Pessimisten]

I would just put 4-5 layers of masking tape on it since it doesn't leave any residue.Thanks, the masking tape worked