Three things:
1. Isolating the color of interest
2. Making it transparent
3. File format
Magic wand is fine, depending on image content. The issue is that if your image is on a background, then it won’t become transparent when you delete the white you’ve selected. Alt-double click the backgrond layer, and THEN delete the white.
Keep in mind that if you save to a format that doesn’t support transparency (like JPG), you won’t see it in your final file.
White isn’t a colour. You can select it by its luminosity, however. I would use one of the channels that most differentiates the white areas from other areas, duplicate the channel, run levels on the duplicated channel to force all medium or dark grey areas to black and most of the very light areas to white. You can then use this modified channel to select the white areas of your original image (load selection>special channel). Dbl click the background layer to make it a non background layer. Then use the menu "select>inverse" and click the layer mask button.
I’m not much of a fan of the magic wand. Unlike "select colour range", it creates an all or nothing selection. Of course you can feather this or even have the feather option set to a non zero number before using the wand, but all that does is blur the edges. It blurs all edges equally, rather than blurring more the almost white areas and having sharp borders for the light grey edges.
I’m not much of a fan of the magic wand. Unlike "select colour range", it creates an all or nothing selection. Of course you can feather this or even have the feather option set to a non zero number before using the wand, but all that does is blur the edges. It blurs all edges equally, rather than blurring more the almost white areas and having sharp borders for the light grey edges.
I, on the other hand, use it all the time – once you use the magic wand, provided you have a fair appreciation for how it works and how to set it, you can create an alpha channel and tweak that – especially for a white background.
