What makes a good (sampler) pad?

[NigelG]

I have a Doepfer Dark Energy which sounds lovely as a pad, but Mono only.

Hooking up my 1010 Blackbox sampler and the poly pads just sound rubbish.

Pretty sure this is down to my choice of samples, so what makes a good poly sample chord sound?

[Jesse Johannesen]

I have a Doepfer Dark Energy which sounds lovely as a pad, but Mono only.

Hooking up my 1010 Blackbox sampler and the poly pads just sound rubbish.

Pretty sure this is down to my choice of samples, so what makes a good poly sample chord sound?

So in my book the characteristics that make up a good pad are generally as follows:

Long attack and decay
  This one seems to be the most important. This provides the feeling of slowly changing, evloving sounds that are good at providing the atmospherics of a piece.

Higher frequency content
   If polyphonic parts all have a shit ton of bass the mix gets swamped, so for pads, use a part that is high pass filtered to whatever criteria you decide, or use a sample that doesn't have a ton of low frequency content to begin with.

Modulation
  To add to the feeling of evolving, it is good to take a sample that has movement happening, so you could crossfade between two sources ( and back) to get the sample, or filter (hp or bp, low resonance) the sample during playback and modulate the cutoff to create that movement. It doesn't need to be synced to the tempo either, just slow.

Those are the things that jump out at me, I'm super interested to hear what others have to say on the subject.
Jesse