Thumbnails

This tutorial is for photo quality images, not line drawings.
I've not tested it on line drawings and can't guarantee the results.

Open an image. If you happen to have the original saved as a .tif, tga or other format, that is the best to work from. Due to compression, Gifs and jpgs lose quality when saved. Re-editing them will not give the same degree of quality as the other formats.

Press shift+D on your keyboard to duplicate the image. Do not work directly on your original!

If your image is a gif, (I hope not), increase the color depth to 16 Million.

resample window From the menu bar select Image/Resample

Select the Custom Size radio button

Type your desired width into the left box (where you see the 45 in the sample picture). Don't worry about the other dimension, it will automatically adjust.

Be sure to check the Maintain Aspect Ratio check box.
Click ok

The Finishing Touch
Select Image/Normal Filters/Sharpen once.
Save

larger thumbnail
75x55
45x33