I believe there is a thread already about this. Here is what I did.
Option A
Open new item in new tab. (t-shirt)
Find Old item to be copied (tote bag) open in design
1. Select all items to be copied (drag on design area, or Hold/Click on the fields at left.
2. Copy
3. Go to NEW product
4. Ctrl-v to paste (didn't work)
5. added an element (square)
6. Ctrl-v to paste (IT Worked)
7. Delete the unnecessary Square element.
Option B
1. Select the item you want to copy from in your STORE MANAGEMENT section
2. in Drop down list at bottom select ACTIONS/TRANSFER
3. Choose the product to copy item to
4. This works most of the time (my test had white text on a dark background. When I copied to a white t-shirt, I lost the text (even when I changed the shirt color).
I hope this helps to answer your question.
