Antialias is a way to smooth out the pixeled angles and curves of a linear image so it doesn’t look so bumpy around the edges. To a black figure, for example, antialias adds pixels in various shades of gray. Which is great. Except:
I craft a neat black glyph on a clean white background using antialias. Save the file & open it again. Gaaahh, it has sprinkled in extra pale gray pixels all around the formerly clean white background. No thanks, Paint Shop Pro 5.0! That wasn’t necessary! So I erase all the intrusive pixels, save and close. Open the file again — the gray pixels are sprinkled in again. Every time.
Is there any way to clean up the white background permanently?
And that, my friend, is most likely where your problem lies. Everytime you save a .jpg, it degrades a little more due to the compression. My advice to you is to use the .psp (Paint Shop Pro) format as you work on it, then save it as a .jpg just once after you have completed your tweaking.
The grey pixels could also be as a result of the .jpg compression. I.E. jpg artifacts. Be sure to save the file at the lowest compression/highest quality.
Additionally, as Kepi said save the file as .psp format until you are completely finished working with it.
O.K., I just experimented with a graphics program, NOT PSP, but the results should be similar.
I created a simple graphic, black on white. Saved as high quality/low compression. Re open and no grey artifacts. Saved again with 40% quality then reopened. Grey artifacts sprinkled liberally about.
Save your file with high quality and your artifacts shouldn’t be a problem. And as Kepi said, save as PSP format until all creation is complete. Might try GIF, or PNG, format too. GIF/PNG supports 256 colors, so black on white should be no problem at all.