An embroidery hoop can be used to hold your jumper tight, but it is not vital.
From the guardian.co.uk
So far, started the embroidery hoop article and added references to crochet.
From the en.wikipedia.org
Secure one piece of the background fabric on to a small embroidery hoop.
From the guardian.co.uk
A colleague gave me a trivet she made out of an embroidery hoop filled with wine corks.
From the sacbee.com
Craft a card wreath with a 14-inch embroidery hoop, mini wooden clothespins, wood glue and holiday cards.
From the timesunion.com
The other, eyes closed, lets the embroidery hoop, the taut cotton, the thin curved needle lie in the folds of her skirt.
From the buffalonews.com
The Singer's needle went forward and it went backward, and if you wanted to do something fancier, get yourself an embroidery hoop.
From the post-gazette.com
In both canvas work and surface embroidery an embroidery hoop or frame can be used to stretch the material and ensure even stitching tension that prevents pattern distortion.