CCT = correlated color temperature (basically the ratio of blue to red light in the spectrum)
It tells you a what temperature an ideal black body radiotor would have to be to emit this kind of white light. (Hotter = more blue content)

BBL = black body radiator line
In many LED datasheets you will find a XY-graph with the different tints Bins of that specific LED plotted on it. Each tint Bin shoes you the CCT range of that Bin and where it is in relation to the BBL. The “tint” is basically the discoloration of white light. The BBL is a horizontal line that goes through the middle of these graphs. Any point on this line is white light of a specific CCT without any “tint” (no green, no yellow, no pink, etc.).

Dedoming/shaving a LED causes it’s tint to become more greenish-yellowish and lowers the CCT a bit (usually by about 500-1000K). So to get a LED that will be close to the BBL after de-doming/shaving it will need to be below it beforehand.

It’s adviseable to search the forum and google with these terms to get more infos. :wink: