Grey edges in sprites with transparent pixels

Hi, I have a problem with my sprites which hold transparent pixels, when they are rendered, grey edges appear around them.

I alredy did some research and apparently the problem lays in how photoshop handles the background of an image with transparent pixels (saving it as white) and when the image is rendered the pixels next a transparent area are mixed with white, creating this grey/white border.

The solution given to this problem is to add an alpha channel, color the empty pixels around the image with the same colors of the pixels of the edges and then fill the background with a color to remove all the remaining empty pixels. It didn't work at all.

I tried the flaming pear solidify method, the fringe+dilatate method, the solid color background method, I kept the layers separated, I merged the layers, I used a background layer called "Background", I imported the file as .psd, I used png, png 8, png 24, super png, save for web and none worked.

In unity I'm using these settings:


I changed them in every possible way and nothing worked, almost nothing..the only way to have those edges gone is to set the "Filter mode" to point; I don't like it though because the texture appear pixeled and I don't want that.

Also I get this error too (which doesn't prevent the game to run), don't know if matters or not:
importer.GetNPOTScale() == TextureImporter::kNPOTKeep
UnityEditor.DockArea:OnGUI()

What else, the sprites I'm using are multiple sprites, I tried 100x100 pixels and 200x200 pixels sprites, inside canvas of 1024x512 pixels, 512x512 pixels and 512x128 pixels.

I create the sprites this way:
I make a new ps file, lets say 100x100, RGB color 8 bit, background transparent or color and color profile sRGB IEC61966-2.1, square pixels.
I paint the textures I need on different layers then I expand the canvas and move the sprites around it; at this point I try the methods I listed above, save and import the file by drag&drop from my save folder into unity.
I select the image. set it like the screenshot above and attach the sprite I need to a prefab which I instantiate via script.
This is the prefab:


I think unity reads the alpha chennel correctly, because it removes the solid color from the sprite sheet and the sprite editor slices the single sprites perfectly.

If I use a single sprite, not a sprite form a sprite sheet, I mean a single image with a single sprite with some transparency and a single photoshop layer (no solid background color) and I save it as a png without even create the alpha channel..guess what. it works, no grey edges at all..which could mean I'm doing something wrong with the sprite sheet since multiple sprites don't work and single sprite does work? I don't know T_T

Please help me, thanks.

 

Do you mean like this?



That's a 512x512 sprite sheet, with 200x200 sprites; I created the sprites, then the alpha channel and I used the flaming pear solidify B filter, which should do what you suggested I believe; it doesn't work.

Here are the settings, the sprite editor and the result:



If you didn't mean that, can you explain it again please? Thanks a lot.

 

That worked! Thank you very much!

May I ask you how did you avoid to bleed the wavy part? I had to duplicate the layer, bleed the copy, select and erase the unwanted part and merge the layers again.

Also in this tutorial (http://docs.unity3d.com/Manual/HOWTO-alphamaps.html) they create the alpha without the bleed, isn't that wrong then?

Thanks again!

 

it also solved by Using wrap mode= clamp with filter mode bilinear or trilinear