Read part 2
Read part 3
Read part 4
Before we get on to assembling the quilt, you need to organise some supplies. A quilt is a 3 layer sandwich:
The quilt top - the pretty bit you have spent ages making.
The wadding - the soft fluffy insides of a quilt that makes it warm.
The backing – usually plain fabric.
Wadding and backing basics
There are loads of different types of quilt wadding. (Americans call it batting) Some is made from natural fibres like cotton, some from polyester, and some are a blend.
The polyester wadding is inexpensive, and comes in different thickness. It doesn’t shrink when washed. I used 2 inch polyester wadding in the first quilt I ever made. We use this quilt everyday on the sofa and it has turned super soft and snugly.
The cotton wadding gives a more traditional flatter look, and generally I prefer this, especially for art quilts that hang on the wall. It will shrink a bit when washed so either pre wash it, or embrace the antique puckered look you'll get in the future. The cotton wadding is more expensive but lovely.
There are more expensive alternatives like wool or even alpaca if you want to go for warmth.
If you buy wadding on the internet it is generally sold in pre-cut bed sized pieces, so you will probably get quite a bit of wastage. Most fabric shops will sell quilt wadding by the metre and this is your best bet for avoiding leftovers. John Lewis also sell wadding.
I bit a rather expensive bullet a while ago and bought a whole bolt of cotton wadding. It seemed a big outlay at the time but it was sensible because I make alot of quilts. I haggled the price down with the fabric shop man because the wadding had gone a bit bobbly.
Extra thrift tip: Keep all scraps of wadding, however small. It makes very good stuffing for soft toys.
For the backing you need another piece of fabric just larger than your quilt top. My local fabric shop sells bed sheet seconds for £2 so I often use those for backing. Also I use cream calico quite a lot as it’s very reasonably priced. Recycle an old bed sheet if you have one spare. If you don't have a spare I bet your Granny has. If you want the backing to co-ordinate with your top you could buy some matching cotton.
Your quilt will probably be wider than your backing fabric so you will have to join 2 or 3 lengths together. It might seem like a waste, but put the seam down the middle, not to one side. I know it means ending up with 2 thinner off cuts, but an off centre seam looks like a mistake. You can always use your off cuts in another patchwork project!

Similarly if you need 3 widths to make up the desired size, put your seams symmetrically like this:

Of course if you are using a bed sheet no joining will be required!
Hope you like my little diagrams! Please don't reproduce them without asking me first.
Your quilt will probably be wider than your backing fabric so you will have to join 2 or 3 lengths together. It might seem like a waste, but put the seam down the middle, not to one side. I know it means ending up with 2 thinner off cuts, but an off centre seam looks like a mistake. You can always use your off cuts in another patchwork project!

Similarly if you need 3 widths to make up the desired size, put your seams symmetrically like this:

Of course if you are using a bed sheet no joining will be required!
Hope you like my little diagrams! Please don't reproduce them without asking me first.