Back in January I wrote a pretty long post about using snaps and went over some of their good points, and options for attaching them. This post talks how to place them on your projects.
It is important to get them in the right place, and neatly installed. They are very visible, which is part of their charm, and it's going to be obvious if they are crooked.
It is simple to put them on neatly, but you'll need to take a few moments to determine exactly where they go. I made a bunch of mistakes, so you can just read about them and then avoid making them yourself.
Before You Apply the Snaps
Long-Prongs - Use "long prong" snaps whenever possible. The extra prong length is ideal when you have multiple layers because you can pre-set the caps by pushing the prongs through the fabric. This makes it a lot easier to apply them exactly where you want them.
Be Gentle - Be gentle on the cap when squeezing the pliers. You can be more aggressive with the stud, but you can squish the cap a bit if you are too firm. At the end of the placement process I'll show you how I handle it if the snap parts aren't all the way together.
Perfect Placement Positioning Process
Because the snaps are a fixed position they need to be attached with some accuracy.
Between cutting and sewing things start to shift a bit, so I don't recommend using pattern guide marks to determine placement. If a pattern comes with placement guide marks, take them as a suggestion, but determine where they really need to be by placing them on your finished project and looking at them.
Below is the general process I use for determining where to place the caps (cap/socket) & studs (stud/prong ring).
They look a little different the closer/further they are apart, so I just look and move them around until they look good to me.
After deciding on the cap placement, lift up the flap and make sure the studs are going to be in a place where you can apply them. Most of the time there won't be a problem, but do check so you don't run into an instance where it is difficult/impossible to get the studs in place.
2. Double check the distance between the sides of the flap and bottom of the snap are equal.
You don't want to apply them and then realize one is higher than the other, or closer to the side of the flap. I've had to reapply a number of them because I didn't take a minute to make sure they were evenly placed on the flap. :0[
Now I look at the distance from the sides and bottom of the flap (or any other applicable reference points), and sometimes I measure if I'm not fairly certain things are even.
3. Apply the cap(s) by pushing the prongs through the fabric, then loading the socket into the pliers, and placing the pliers over the cap.
When I first started using the snaps, I'd load both the cap and socket into the pliers and then try to aim for a predetermined spot. But the cap covers up your marked spot and it is hard to judge the center of the cap since you are looking at the pliers from the side. So put the cap on the fabric and then place the pliers (with the loaded socket) over the cap.
4. Mark and apply the stud(s).
After applying the caps, close the flap and mark the position for one stud. Do just one first--even if you have two or more to apply.
I mark the position by first folding up the sides of the fabric right next to the socket, and marking that spot with a pin or fabric marker. Then I do the bottom in the same way.
Then I apply the stud using the pins/marks as my guide.
After replacing a bunch of studs I learned it works best to do them one at a time. If you try to mark and apply both studs at once, you can easily end up with a bunched up or stretched flap. Small differences in the stud placement = wonky looking flaps. So go slow and do them one at a time for best results.
Now if you were gentle with your pliers your snaps probably look fantastic, but the parts might need some additional squishing to make sure they are really attached well.
I cover the front and back with scrap fabric and use regular pliers to gently squeeze the front and back together around the edges.