I'm not sure about the tradables myself.
Found this interesting piece of information:
"We are the few owners who own one or more clean black rose/s .
Curently only 32 clean black roses ( tradable and craftable ) are in existence .
A short history :
In the 14 february 2012 the black rose was added in the game. After some few more updates, on the 18 april 2012 update valve stated that it's now tradable but after updating the game files the knife still had the tag "Not tradable" on it . Now it's only giftable ( can be wrapped ) .
Few people who noticed this after a while sended a ticket to valve to make it tradable, because the update states so and the wikipedia too . An uninformed valve support guy ( if i can say so ) responded to the people tickets and made them tradable . Aparently seems that he was uninformed , because The Black Rose is not supposed to be tradable because it's an achievment based item and isn't tradable .
A thread was posted on SPUF named "Black Rose confusion" by the support guy who made few of them tradable and posted info but it got deleted.
You now can see that they are not longer obtainable in the tradable quality. (Click on " Support Tech answer ")
The Black Rose is awarded to players who complete the Alliance of Valiant Arms achievement 1st One Down by creating a character and playing their first game. In addition, this achievement will unlock the Holy Mackerel melee weapon for use in Alliance of Valiant Arms.
If you own a clean Black Rose and want to be a part of this group get in touch with one of the admins from here to invite you . "
Source:
http://steamcommunity.com//groups/blackroseclean
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