making sprites with blenter.annoying problem

i have a problem with sprites made in blender.they look nice on dark backround,but on white backround they have a black edges around them.
any ideas?

if you want hard edged sprites, just turn off osa. if you want alpha mapped sprites, set to file type .png and click RGBA and premul in render buttons. if you want a seperate alpha mask, render your character normally, then set his material to shadeless white and render him again.

You’ll get outlines if the background of your sprite’s image is shown. This happens when you think its hidden with transparency, because often the image colour is oversampled, leaving part of the backround on the semitransparent pixels.
If rendering in blender, you can leave OSA turned on, if you press the ‘key’ button. This makes the edges that cover part of the sky and part object completly the object’s colour, and oversampling the alpha, so by using the transparency you can place the sprite on any background without the sky coloured edges.
If you are using some other program to draw sprites, make sure the background colour is the same as the edge’s colour where the transparent outside meets the sprite’s body.
To use transparency you’ll have to set the face of the sprite to do so and use a texture saved with an alpha channel in either png or tga format.

Sounds like your sprite has a black background color. When the pixels are blurred this often creates a black outline. Try to fill in the background color of your original image w/ a different color. Depending on your paint tools you might have to fill in the background and then erase the bits you don’t want to see.