Ah, vintage patterns….. so lovely, but rarely in plus sizes!
No, worries! I’m going to share a method to MAKE them your size!
Disclaimer: I am not an expert pattern drafter. Take caution when grading up a pattern.
- To demonstrate this method I’m using a one-size vintage pattern.
- I’m grading this pattern up several sizes. Many sources suggest grading up only one or two sizes.
- This is just one method of pattern grading. There are many different methods that can be used to resize a pattern.
Starting Out
For this tutorial, I am sharing a basic method on how to resize a dress bodice. Basically, I am drawing horizontal and vertical lines on a pattern piece and cutting and spreading them apart to achieve a larger size.
These are the tools I used to grade up this pattern:
- Swedish Tracing Paper
- Tissue Paper
- Rulers
- Pens
- Scissors
- Tape
I like to use Swedish tracing paper to trace vintage patterns. You can use whatever tracing paper is your preference. The tissue paper is used for altering the pattern pieces and keeping it together after cutting and spreading the pattern. You can use your paper preference for that as well. Sometimes I also use a seam gauge, but I prefer clear rulers when I resize patterns like this. Sharpies are also not the best if you don’t want ink marks on your table, but they work well for sharing this method with you. You may prefer to use pencils instead.
The Pattern I’m Using
This pattern is a simple design from the 1950’s. If you can, try to use a pattern that is closest to your size. I have a few vintage patterns that are my bust size, but they are difficult to find.
Step One
Before I get into any mathematical equations, I start out by tracing my pattern pieces so that I have them ready to go. For me, it’s important to trace my pattern pieces as I don’t want to cut into my vintage pattern and alter it.
Step Two
Next, I need to find my size on the pattern envelope and compare the pattern’s measurements to my own. I find the easiest way to do this is write down each set of measurements and then find the difference between each one by subtracting the vintage size from my size. I will then split up that difference, distributing it to resize my pattern. I would not just add 7 inches to the seam line, instead I will divide that number and spread it out.
For this pattern piece, I will be dividing the difference between the pattern measurements and my measurements by 4. This is how I reached this number: The 7 inches I need added to this pattern in order to get it to fit me needs to be shared for both the front and back of the bodice, which are 2 areas. As this piece is cut on the fold, I will need to break it down further to 2 more areas. Adding those 2 numbers together gives me the number 4, which are the 4 areas that I need to distribute the overall grade among my pattern pieces to achieve my size.
Equations:
- Your size – pattern size = overall grade
- Overall grade divided by front/back + number of seams (or 2 for fold) = allocated grade
Example:
- 48 (my size) – 41 (pattern size) = 7 (the difference/overall grade)
- 7 (overall grade) divided by 4 (front/back + fold) = 1.75 (amount I need to add to each piece – allocated grade)
Step Three
Now, I need to figure out where I’m going to cut and spread my pattern piece. The diagram above shows some basic areas to increase the size using my figures from step two. You can add more lines, but just remember to evenly distribute your measurement differences.
Here is an example of other areas you can place cut lines.
I then take my ruler and add my cut lines, following my diagram.
Step Five
For this pattern piece, I have 2 vertical lines, so I need to share 1.75″ (my figure from Step 3) between these 2 lines, essentially: 1.75″ divided by 2 = 0.87″.
For the horizontal line, the rule of thumb is 3/8″ per adult size. People generally don’t get taller as they grow wider, so this number is usually enough length to fit. You may want to adjust this to your body type.
Equations:
- Allocated grade divided by number of vertical lines = amount to add between each vertical line
- 3/8 x number of sizes you that you have graded this pattern up divided by number of horizontal lines = amount to add between each horizontal line
I then spread the pattern pieces out on tissue paper according to my figures and tape them down.
Note: I am grading this pattern up basically 3 1/2 sizes, so the equation should be 3/8 x 3 1/2, but I am opting not to follow that rule for my bodice. My preference is to add that minimum amount on the horizontal line that I’ve drawn and then later adjust the original lengthen/shorten line to my preference after I am finished resizing this pattern. I am short-waisted, so if I want the waistline of the dress to hit me at that point, this is how I would do it. I would figure out what works best for you. You have a traced pattern, so you can experiment with what suits you.
Step Six
After I’ve finished taping my pieces to the tissue paper, I draw new lines with my ruler and trim the edges. And there’s my new pattern piece!
For a difference in bust/waist measurements from the pattern measurements, I would figure the maths out differently for each area and grade between sizes, just as I would do for a multi-size pattern. I would either angle the pattern pieces to fit my measurements or draw lines and blend the measurements together.
For grading up the rest of this pattern, I will use the same basic concept on the skirt. Of course this method does not take into account any additional alterations like widening the sleeves or doing a full bust adjustment. This is just an example of enlarging a pattern from it’s initial size. You will need to amend any dart positions on your pattern after enlarging it and do any of your normal pattern alterations.