Dirty edges on alpha channel

I am trying to map graphics created in Photoshop onto a cube.
But when I render the file I get a lot of artifacts around the mask.
How can I clean this up?
The alpha channel in Photoshop is absolutely clean.

I have to do the graphics this way as the client wants a chiseled effect which I had to fake in Photoshop since Blender’s boolean tools suck.

I think I know what you’re talking about, because I get it a lot too. I haven’t found a solution — consider your request for help seconded!

Make sure ‘Premul’ is checked in the Image tab of the Texure panel.

@Sol Blue
Must be solution somewhere. I am using a procedural texture on a cube then mapping a graphic with alpha (from Photoshop) on top of the procedural texture as an image texture. But I get ugly pixelated white lines around the alpha on the cube after rendering.

@Dan_G
I think you refer to rendering out a total background alpha rather than textural alpha. Thanks tho.

I know what you are saying. Its confusing at first. All you have to do is :
In the materiel tab
1] select Z trans
2] Have the Transparency (A) alpha slider dragged to its extreme left
3] In the map input select col and alpha (I presume you have a 32bit tif, tga or a png)
4] load the texture in the Texture tab and select ‘Use Alpha’ in the ‘map image’ section to the left. (provided you have a 32bit tga, tif or png with alpha)
5] This is a crucial step often overlooked. Go back to the materiel tab from the texture tab. In the ‘map to’ activate the ‘Stencil’. The artifacts should be gone by now for good.
Render to check.

it seems to be a bug

use TIFF format - works.

PNG and PSD have artifacts like hell