First, here's what I mean by double-sided ready-quilted fabric. Our local store, Fabricland, has:
...... tartans, shiny, white and black and other plain colours ....
... and a variety of others including camouflage, fruits, and several Christmas fabrics.
I only wish there were even more designs - or at least, more interesting second sides. Some do have another interesting design on the reverse, but most are plain coloured, including a lot of plain white.
So, how can we get a neat edge?
For certain types of seams, you can just use double fold bias binding. This works if you are just making a finished edge, as on this playmat:
In the case of this sleeping bag, this also worked to join the front and back together, as well as to edge round the shoulders and the sides of the zip :
With this toddler rucksack, seen below from the bottom, there were several internal seams inside the bag. The main seams join the back to the side panel, the two parts of the front, top and bottom, to the side panel, and the two ends of the side panel into a circle. I chose to put this last seam at the bottom, seen in the middle of the photograph. None of these seams would be exposed, so I just zigzagged over the two edges of each seam. I don't have a serger, but you could obviously use a serger if you had one.
However, just finishing the edges won't necessarily give you a flat finished seam. You can see in the picture that these seams are not really flat. In general, it is not a good idea to iron ready quilted fabric, as you would with a simpler fabric, because the polyester inside can melt a bit and give you a stiffer, thinner fabric near the seams. And it probably still won't lie flat. Not having flat seams didn't matter for the body of the rucksack, it still works well.
Over-sewing on the outside can help to flatten seams and hems, if you don't mind the stitches showing. You can see I've done this on the straps of the rucksack, above. I also used this as a feature (by zigzagging with contrasting thread) on the strap for the playmat.
However, the most recent sleeping bag I made, using ready-quilted fabric for the back of it, required me to do some thinking about flat seams. The seam would be right across the back, and could touch the baby's skin.
This was because I didn't have a big enough piece of quilted fabric left to make the whole back. I did have two pieces left from the previous projects, neither of which was big enough on its own to make the whole back. But I neither had the time nor inclination to go and buy some more, not when I had fabric left over. (I hate wasting fabric.)
So the other option was to join the two pieces, making the seam lie where I thought it would cause least disturbance to the baby - about at waist level. Even though the seam raw edges would be on the inside, I didn't want prickly, maybe itchy bits of polyester leeching out of the edges on the seam. The fibres are so fine, I thought this could be the case even if I had zigzagged the edges as on the earlier example.
And yes, I know it would have been nicer to have been able to match the pattern. If I'd had enough to do that, I would probably not have needed a seam in the middle of the sleeping bag back anyway. But see how nice and flat the seam is. And it doesn't show when she's wearing it, because it faces her back.
Here's what I did. Note that I was able to have a much larger than normal seam allowance in this case - there was at least 1 1/2" to 2". You could do this with a smaller seam allowance but it would be mighty fiddly.
This step is entirely optional, because it does show on the outside. You can omit it (though the seam won't then be quite as flat), or make a feature of it. There are several alternatives:
- You could just sew one row of zigzag right across the middle of the seam - the same method I used to flatten leatherette seams in the pirate waistcoat. You would have to do this, I think, if you had a narrower seam allowance.
- With a flashier sewing machine than mine, you might have other decorative effects you could use. With only a simple machine like mine (forward, backwards, and side to side are the only controls), zig-zag is as decorative as I can get.
- You could, instead, use a straight row of stitching, to make it more invisible, or several, in parallel, to create an alternative decorative effect. I did this on the toddler rucksack in the same fabric, to make sure the turned under facings laid really nice and flat. (Having sewed a couple of rows, I liked what I saw, and added more rows.)
Step 2. I then gently pulled apart the backing and front fabric of the rest of the seam allowance not held flat by the zigzagging.
This enabled me to trim down the backing and the polyester wadding from the seam allowance, leaving the front fabric untrimmed. (Your goal is to have enough left - maybe half an inch or so - to fold under the main part of the seam allowance.)
Step 3. I folded the front fabric back under the rest of the thicker part of the seam allowance, and pinned it down.
Step 4. I hand-sewed the hem thus formed. So the polyester wadding was now enclosed in my hemmed seam.
You could, instead, over-sew it, zig-zag along it or what ever, but I thought I had enough fancy work showing on the outside, and my seam was only about 15" long. I don't mind hand sewing at all on short bits. So, a finished flat and reasonably neat seam, that won't cause the baby any problem at all.