PNG save for web: unwanted white border

[CLou]

After exporting my PNG file a white border shows up arround my design. The transparancy of the white white fade becomes a non transparant troke/blur. Below 3 images which shows te problem:

1) Original design in Photoshop

http://imgur.com/4lgHJCY

2) Settings for exporting as PNG (PNG 24, Transparancy on, can't change Matte settings)

http://imgur.com/vaWtcaE

3) Image after exporting (png looks good after exporting but by using it for the web, for example when I want to email it, the white border shows up. http://imgur.com/91qmsiR

Does anyone know how to solve this problem? Thanks for helping.

[davescm]

Can you link to the actual PNG file ?

Dave

[CLou]

Yes ofcourse, here is the link: Imgur: The most awesome images on the Internet

[davescm]

Hi

There does not appear to be anything wrong with the PNG file that you posted.

It looks like whatever you are using to combine the file with the background later is not correctly treating the transparency channel in the PNG (a PNG has RGB and a transparency channel)

Dave

[davescm · Accepted solution]

I tried opening your PNG in Photoshop above a black layer and it looks correct - I also did the same placing it in illustrator . Both treated the A channel correctly as transparency.

When placed over a black background layer both looked as below:

Dave

[Francesco Della Peruta]

• At this point i think that the problem depends on the other software like your email software that cannot handle in the correct way the transparency option of the png

[Francesco Della Peruta]

Hi, but in Photoshop file is the background Transparent?

the black in the background is on a separate layer?

or are you tring to replace black background with transparency?

[Francesco Della Peruta]

If so Maybe you can optimize the result using selective color selection on the black background and erasing it, leaving transparent background. Then export the file to transparent png format.