The date for this piece is 1975-9, as there is a dot below the letter E in COPENHAGEN.
For a full summary of the dating systems and variations go to the RC website On the above back stamp, the painters initials LB are to the right of the stamp.
The numbers on the back stamp are not unique to the piece. In this case the pattern number of the piece is 870, and it is painted on shape number 3726 - if you look back to the previous post you will notice that the blue-bird bottle and the black and yellow bottle by Nils look the same shape - and they are - they are both shape number 3726, but of course have different pattern numbers.
The logo or cypher at the bottom is the stamp for a Nils Thorsson design - has a comprehensive record of nearly every designers stamp on their website.
This piece is not etched through the wavy lines, and thus not a second.
The back-stamp on any piece of Royal Copenhagen contains a lot of useful information to the potential buyer.
As well as identifying the Designer, the painter, the shape number and the pattern number – the back stamp will indicate if the piece is a factory second.
It is important also to know if the piece is a factory FIRST, or factory SECOND as often the appearance of the piece will often give no indication of it being a second.
However a second mark will usually mean that the piece is worth less depending on the rarity and popularity of the piece, as seconds were sold at a 25-30% discount at the factory shop.
Pieces coming out of the Royal Copenhagen (and usually Alumina) factories which did not meet the standard for perfection are marked as a second.
This is/was done by etching (usually 3) short lines, through the 3 Royal Copenhagen lines with a diamond cuter.
Often this marking is invisible to the naked eye unless it catches the light, so with every piece of Royal Copenhagen it is best to run a finger over the back stamp, and you will feel immediately if the piece has been marked. Most often it is something like a small dent, or firing crack, irregularity, or an error or fault in the painting on the piece, however sometimes there seems to be nothing at all to indicate why it is a second.
So lets look at the other identifiers on the back stamps, using the piece by Nils Thorsson from the last blog post.