The tank dress pattern is made up of
1) The tank front.
2) The tank back.
3) The skirt back.
4) The skirt front.
To create the dress, basically you line up the waists with the waists.
Make a point under the waist on the tank pattern, to correspond with the difference.
But I'm not going to take the easiest option here. I want this to fit well. And if I have learned anything from making my own clothes, its that I really need darts in the back, even for stretch dresses otherwise it hangs like a sack and I loose all definition.
|Back darts are good.|
To be honest, most of this I just eyeballed. There's an element of science with all of this, but figure variations cause so much complexity, sometimes going 'Hey that looks about right' seems to yeild better results than being complicated about it. But I do make a lot of comparisons with my existing clothes.
I wanted darts that pulled in about 2 cm. They will be 1cm deep when finished. The widest part of the dart is on the waistline. I got this figure when I made the shirt, and found that I could comfortably remove 4cm from the back to get the side seams to line up with my body, and the back to fit snugly. Don't pull back further so the side seams swing out - you want a straight line down the side of your body. You can add darts even if you don't have ease to work with, if you add it back in on the sides. (I've got a picture of this at the end).
Take your (tank top + skirt =) dress back, and trace it out. Include the waist and hip line. Draw a line across touching the bottom of the armscye too.
You should have something that looks like:
You now need to decided where your darts will go.
Keep in mind that the centre back line is on the fold. So if you put the dart exactly in the centre of this piece, it will be across to the side of the finished garment. If you lay your t-shirt or tank on a table, back towards you, you can pin where you think the darts should go, even try it on and check in a mirror. Once you have done that, measure the distance apart, and then halve that distance. That is the distance your dart should be from the centre line. Place your first dot there on the waist line.
When you have decided where your darts go, draw a perpendicular line through the middle, which sits exactly between the dots you have made, and extends from hip to armscye line.
You probably want your bottom dart to go half way to your hip line, or less. Depends on your bottom. One way to get a good idea is to have a look at the length of a dart on a skirt or dress that sits nicely, and measure that. I did that, then I chose a spot and put a dot on it.
Join the dots, and make a diamond.
If your design was already snug, increase the fullness at the waist, by adding the 2cm or so you put into the dart back at the waist, and blending that line with the armscye and hip point. I chose not to do that, because the shirt I made without darts had more than enough extra fabric swimming around my back. If you did, it would look a little something like this:
The first time you make this back, baste your darts as you construct your dress. Then go back when it is otherwise finished (or at least front and back basted together) and check. You may want to move the dart up or down to sit nicely. If you have a very curvey shape, it might even be worth considering using two darts. This is a design process, so play with it a bit. My bottom is constantly at war with the darts on commercial clothing / patterns, because I am short between hip and waist, and my hips are narrow, but my bottom sits out. My figure on profile is a heck of a lot more hourglass shaped than from the front. None of this mattters, because you just play with it until it looks good.
When you settle on a position you like, draw the corresponding dart point on your original pattern, and it will be ready for the next garment.
I then used this darted back, and my tank front+skirt front to create a simple tank dress.
It looked like this:
I used a narrow hem to finish the arms and neckline. Once the pattern is sorted, this dress is really quick to make. Also, I am going to use it to form the foundation for other stretch dress designs.