We buy a big pack of cheese slices from Costco,is it possible to freeze half of them as we lose a few due to mould.

Yes but ensure they are separated. If they come with sheets between them that'll be fine.

Generally the harder a cheese is the better it freezes.
I find softer cheese tend to go quite mushy after freezing - ok in soups and sauces though. Anyone know a top tip to freeze soft cheese?

Nope, all the advice is that they don't freeze well - but I do it anyway.
You'll find that with Camembert, for example, the rind will separate.
I still find it edible though.

Thanks all it isn't separated I'll have to cut up some greaseproof paper.

I freeze all kinds of cheese but it does tend to crumble when it has defrosted - not much good for sandwiches but great for cooking etc.

Lakeland sell rolls of Easy leave, perforated sheets of thin plastic type of cling film, (not cling film, and it does not cling), especially for interleaving food for the freezer. it is very good, about 300 sheets for about £4.00.I use it to wrap cheese and sausages etc, for the freezer.

Thanks I'll try and get hold of some

The packs of cheddar cheese slices I buy come individually wrapped.
Packs go in the freezer until ready to be used.