Following my recent shirt waist dress project I thought I would write (and draw :) a little tutorial on how to add a button extension to a bodice pattern. A button extension can be added to any bodice back or front as long as the bodice is not too tight (gaping!). In this case a little ease added on to the bodice will help to prevent gaping. There are two different ways of adding a button extension to a bodice. First:
FOLDED BUTTON EXTENSION
For this extension you add onto the bodice center front (or back) the required amount for folding over the edge for a button extension. In this drawing you can see the button extension that needs to be added on to a bodice front. The broken line is the center front line. You want to place your buttons along the center front line, therefore you have to extend the bodice on both left and right side so that they can overlap at the center front.
The part that is filled in red is the extension you will see at the front when the garment is finished. The blue part matches the red part exactly, only mirror reversed, and folds back. The last bit is the seam allowance you need to add on. Especially with smaller button extensions I make the seam allowance as wide as the extension itself. So this means that for a button extension that is 3 cm wide you will need to add 1.5 cm (half the front extension from CF) + 3 cm (full extension for folding) + 3 cm (or less - for seam allowance) = 7.5 cm. When you fold your extension it will look like this:
You won't see anything at the front and you can either just fold the extension without any sewing or fold it and sew the extension shut along the edge (shown in pink). I usually choose not to sew the edge. Once the buttons and buttonholes are sewn into place the extension will no longer unfold but stay put.
SEW-ON BUTTON EXTENSION
Another method for adding a button extension to a bodice is by adding a sew-on extension. This is useful in case you have already cut your garment and decide later that you would like buttons along the front, or if you have too little fabric to cut the whole piece in one. This method is also useful for refashions. Any old t-shirt or sweater can be made into a blouse or cardigan by adding a sew-on extension.
In the drawing you can see the sew-on extension. It is twice the width of your desired extension plus seam allowance on either side. It is folded over your center front or back and then sewn at least along the inside edge (pink), and optionally along the outer edge, through all layers.
DETERMINING THE SIZE OF THE BUTTON EXTENSION
Before you draw your extension onto your bodice you have to decide how big the buttons you will sew on will be. The size of the buttons will determine the width of the extension. I sometimes forget to calculate what width I need beforehand and just go with whatever width I fancy for the style, but this sometimes ends up in uncentered buttons. So, I generally recommend to decide on the size of buttons beforehand. This diagram shows, what I consider, the correct placement of buttons on a buttonhole extension:
The button should be placed excatly in the middle of the extension and should be half a button size away from the side edge. So, if say, your button is 2 cm in diameter your extension should be 4cm wide. This way you can place your button right at the center and with half a button width away from either edge of the extension. I don't have a hard and fast rule for the distance between the top edge of the extension and the button, but I would say it should be no less than half a button width and no more than the full width of the button.
PLACING BUTTONS AND BUTTONHOLES CORRECTLY
Buttons should obviously be spaced evenly and sit right at the center of the extension. Depending on the style of the garment and the size of the buttons the distance between the buttons can vary. However, always consider that a button should be placed where the apex of the bust is to prevent gaping. This is really important, particularly for the more busty among us. Threads has a great tutorial on button placement.
For buttonholes, have a look at this drawing:
I used to sew my buttonholes so that the middle of each buttonhole would macth the center of the button, but this is not the correct way of doing it. Your buttons will be centered and the center fronts (or backs) will match up if the center of the button corresponds to the inner corner of the buttonhole in a horizontal buttonhole and to the upper corner in a vertical buttonhole. It makes sense if you think about it, because when wearing you will naturally stretch the front apart and/or the blouse will hang, pulling down. Naturally the buttons will come to rest at these points of the buttonholes.
One last note: Don't forget to interface your extensions before sewing!
I hope this tutorial was helpful to some of you and inspired you to make yourself a shirt dress for the June Challenge. Happy sewing!