10c Queen Imperforate Block Of 4?

Hi all,

About 20 years ago I came across this at an American stamp dealer's shop while browsing through his Canadian stock. He was selling it as a regular block of four, so I picked it up for a few bucks. I did not know what it was, but I knew it was odd with the lack of perfs horizontally so I bought it.

However I'm having trouble identifying it. Unitrade refers to imperforate pairs, but these are not imperforate - they are perforated vertically.

There is a faint trace of a scoreline on the back in the gum. I've seen some of these pairs list for $100 or more on ebay, but again I'm not clear on the categorization.

Thanks for any help you can offer!

These are coils (# 605) and to be scarce they have to be 100% imperforate without any hint of any separation line.

These are fairly common with the score line. They are unsepperated coil stamps. They also show up without the score line and these are the true imperforate between stamps which are much rarer.

They were originally sent to Post Offices in "tubes" of ten rolls, with the coil rolls attached slightly. The Postal clerk would break or snap of a coil roll from the tube when he needed a new one.

Some users would buy an entire "tube" or perhaps two rolls that were still not snapped apart.
If you unrolled the connected rolls carefully, you could then get a "block" of four with the horizontal "imperforate".

This was not difficult. The real prize was to find a block where the connected coils had no scoreline AT ALL. This was a very rare occurrence, hence true part-imperforate blocks, as watermark and jogil mentioned, are almost non-existent.

The ones you see on ebay are questionable. With a good glass, even a faint scoreline means it is not worth a premium, except perhaps as a novelty.