[BobandJack]

I've come across a piece of opaque plastic in a sort of frame (thought it was a glass window whe I picked it up)  Would it do for the lid of a cold frame or does the "glass" need to be clear?  Would it let in enough light do you think?

[paintedlady]

my cold frames are made of opaque white plastic and the plants are fine.  In full sun it will be bright enough and keep the warmth in (a big factor) and by the time the plants are big enough, you should be opening the lid anyway to start hardening them off.  Go for it 

[Sadgit]

mine is half glass and half opaque plastic. Because the cats jumped on the glass and smashed it. Will all be opaque plastic soon, as I don't want the cats doing it again on the other side.

[Babstreefern]

I have 2 coldframes.  One is inherited from the last owner of my allotment, which is all glass - walls and top - its ex-double glazing complete with frame.

The one I brought with me from my previous allotment, is the one my hubby made which has wooden walls and a clear plastic top.  I've read somewhere that to make a coldframe you can even dig a hole in the ground and just put a glass top on it. 

By the way, my coldframes are in partial shade/sunlight.