Coverting colored background to transparent 1

[dark2]

I had tried to convert a colored background to transparent following the thread229-1271520 and it worked perfectly. However my real work was to create a compositon with multiple images (the ones with transparent background) and when I put all images together the "transparent background" of each one wasn't totally transparent. I could easily notice because I was moving one image over another and wherever the "transparent" background layed on the image behind was a bit lossy. Did I miss something? Should I change the preferences? How can I ensure the background would be completely transparent when printed? All images were scanned on the same machine. I am using Photoshop CS.
Thanks,

 

[eugenetyson]

Make sure that your brush or eraser tool you are using is set to 100%. And make sure you haven't made it too feathery. If you make a new brightness contrast adjustment layer over one layer you will be able to see the bits you missed when you were removing the backgrounds.

 

[dark2]

Hi, I finally had a chance to try your suggestions on this project again...and it worked!!
Thanks you so much!! I had missed the feather...