CLEAR is the top of the line in any wood.
This is an architect's grade - the rarest part of the tree, the hardest to get, the most expensive option. Clear and Clear Vertical Grain (CVG) are the Highest appearance grades we have.
But even CLEAR grades rules allow knots. They may be tiny, they may be few but they are allowed in grade rules. In Buffalo Lumber Layman Terms - If we were talking about a 1x8" board 12' long, the AYE&BTR Clears will allow 2 knots per board no bigger than 1 inch.
Where's Waldo? You have to really strain but here they are there ...
These grade rules represent the maximum to expect per single board - NOT all boards. The majority of boards should be completely clear or with one small knott per 12' length.
The picture above is perfect in demonstrating the subtleties we are talking about. At first glance the image looks completely clear. But if you take some time you can see there are at least 4 knots visible.
YES - there are knots allowable in a clear cedar grade rule description!
I found this out the hard way when we sourced from a mill who used the grade rule as a "what can we get away with per board" rather than a worst case scenario.
The result was 1 to 2 knots on every board and we had no recourse with a grade dispute.
Grade rules are intended to be the worst case allowable on a board - but NOT the entire order.
When interpreting grade rules this is where the integrity of the mill really comes into play. We do not expect every board in Clears to have 2 knots. We expect some to have that but almost all will have one or none.