This tutorial uses PSP masks.
Open your image (if it is in GIF format increase the colors to 16 million)
Create or open your mask pattern.
It doesn't matter how big it is,
it will conform to your image when you apply it.
Create a new layer on your image.
On this layer select Mask/New/From Image settings;
Source=name of your mask, Create mask from source luminance,
Invert mask data checked.
Next use the flood fill tool to flood this layer
with the background color of your choice.
Your mask does not have to be made with the selection tool.
This mask was made with a dingbat font and a little Selection Modification.
It has been expanded by 5 and feathered by 20.
I used the same method above to apply this mask to a friend's baby.
Make a selection over your image.
Choose Selections/Modify/Feather and make the feathering large. I did 50 pixels.
Set the background to your color choice and click on delete.
Faint Yellow background
An alternative to this method is the Misty Edge method
Open your (16 million color) image, and make a copy of it.
Paste it on a new image twice its size. The color of the mist will be
the background of this new image. Do not deselect once your image is pasted.
Now choose Selection/Convert to Seamless Pattern,
and there you have it!