(((((( Yes, you can embroider on a FO. The duplicate stitch merely recreates the stitch in a different color and has many applications; It looks fab, too.
Other embroider stitches, too can embellish an FO:
Lazy Daisy
French knot, etc.
For embroider stitch how to/s, surf for:
Embroider stitches
......then view the draw.
A good how-to book (hand knitting, crocheting, etc.,) will also print these at times so one can have them when away from computer access.
When you draw the options up, you'll see tons of stitches that might interest you, too and I would think that the objects you want may be there.
Another thought, also is to choose classy buttons for your FO. I've seen plain sweaters with no embroidering, nicely done, though and the buttons really set it off.
You can get variety buttions, also in the notions departments and no doubt find trains, etc.
Good luck!
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Suesea said:
I am in the process of knitting my first sweater for my 1 year old grandson. It is a stockinette stitch in one color, fisherman off white. (Since it is my first sweater, I didn't want to start off with a difficult pattern with lots of colors to deal with, but now I see that it will be very plain when completed.) Is there a way to embroider an object (car, train or boat) onto a completed sweater? What is duplicate stitching?