Strange shadows, weird lines show up after printing

[marciad5]

Tonight I went to a scrapbook store to print out all the pages I've made for my daughter's wedding scrapbook. Afterwards, I looked at them very closely and noticed some strange things and since I'm new to this, don't know how to fix. I did them on photoshop 7. Thank goodness I copied each page before saving as a jpeg. Before saving them, first I flattened all the layers and then saved as a jpeg. Should I not have flattened? On some of the pages, it looks like bottom layers are showing through the top layers. Does anyone know how I can fix this?
Thanks, Marcia

[esther_a]

You did the right thing saving both your layered version (.psd file?) and your jpg version. You don't need to flatten before saving as jpg because PS does it automatically for you. If layers are showing through then it sounds like the top layer is a bit transparent. Open your original layered .psd file and find the offending layer in the layers panel, click on it to select it and check the opacity at the top of the panel says 100%