This treatment helps you to alter an existing garment by cutting a new opening and finishing the edge with a trim.
For example, you might create a new, more generous neckline. Alternatively, you might convert a jumper into a cardigan with a new front opening. The technique is familiar in nordic and fair isle knitting, where cardigans are knitted in the round.
There are various ways of working this treatment. The trim could be knitted separately and sewn on, or knitted off the existing fabric.
The typical method described for a front opening in nordic/fair isle knitting is to cut the fabric and pick up a few stitches in from the cut edge, to make a sideways 'knitted off' trim. In Knitting Around, Elizabeth Zimmermann suggests folding the cut edge under and tacking it down (p172). Kate Davies suggests an alternative method, which encases the cut edge in a 'sandwich' of two layers of knitting. Detailed instructions (intended for fair isle knitting, but adaptable) can be found on her blog here.
Montse Stanley includes some other suggestions for finishing cut edges by knitting off or joining a separate piece in Handknitter's Handbook (p240-1, 257).
not yet developed
You can see examples of this treatment in the gallery: