Portraits

[traci_barbour]

No: HPFGUIDX 74923

I have a silly question that may or may not have been previously 
submitted but I've checked the archives and can't really find 
anything that satisfys my inquiry.  Perhaps one of you could help 
answer this question? - 
What determines the qualifications of who gets a portrait made?  I 
mean, we all know the portraits hanging in Dumbledore's office were 
all past Headmasters/Headmistresses but what about the other various 
portraits hanging around Hogwarts?  I'm assuming that those portraits 
are of people who are significant in some way or the other.  If 
communication between the living and those deceased in the portraits 
are easy, then one would assume every portrait produced is capable of 
communication right?  Although we know that until Sirius' name is 
cleared, the likelihood of his portrait isn't under consideration but 
what if in future books it is?  What if his portrait is painted? 
Would he then be able to communicate to Harry?  We know that 
these "enchanted" portraits are not only confined to Hogwarts as 
Sirius' mother's portrait at the Black house is able to react to 
outside disturbances whenever the sheet covering is removed.  I am 
curious to hear other's thoughts on this.