So you’ve made a lightbox and you’re ready to take product photos. You’ve got your seamless white background and good lighting, but the products still have some gray areas around them. How can you make the background pure white for consistency? If you have Photoshop, it’s no problem.
First, open up your unprocessed product photo. (…this probably should’ve been taken with better lighting/exposure, but it’ll do.)
Crop as close to the product as you can get without cutting off its natural shadow at the bottom.
Go into your Levels and adjust them using the Auto button. This will naturally brighten the picture.
Then select the eyedropper all the way to the right to set your preferred lightness. By clicking on the gray area next to the product, you are adjusting how the program perceives its lightest levels. So the gray will turn into white and the rest of the levels will adjust accordingly, brightening the whole deal.
Ta da! Now you can copy and paste the image into a document with a pure white background without worrying about patchy gray areas.
This works the best if the photograph itself is originally taken with ample lighting and good exposure. If the white background is registered as too dark, then Photoshop will go to more extreme measures when it adjusts the levels. It can be a nightmare processing photos of things that contain a lot of white if the lighting is bad.