Custom Style

Sewing that's Retro, Geek, and Chic

Pattern Sizing Experiment: Part 2 – Testing Three Mockups

So I left all you readers with math swirling around in your heads. I hope Part 1 wasn’t too technical or too much of a cliffhanger!

Now I bet you’re eager to see how my experiment worked when I applied the math. =)

First, I copied my pattern in the bust 34 size at 91% on my printer and taped the pieces together. (As always, photos enlarge when clicked.)

I just cut through some of the easy-to-match parts of a page in order to line it up and tape it to the corresponding part on the next page.
No need for straight lines.

I used some of my favorite pattern tracing paper to trace the other two copies of my pattern at the same size they came in – one bust 34 and one bust 31 size.

Because my traced patterns were on such sheer paper, I could do a good comparison of the shrunken 34 under the actual 31 to see the minor differences.

I lined the two patterns up along the center front neck edge.

The differences were subtle but interesting. Here are a few closeups:

Pencil-marked pattern on top is the true 31 bust size.

To me, the most fascinating part of the pattern comparison was the keyhole detail at the neck. When patterns are graded by the manufacturer, many of the details are not proportionally scaled, meaning that some details remain the same size no matter what size a pattern is drafted to be.

All three keyhole cutouts compared within the actual bust 34 sized neck-facing piece.

This means that on a smaller version of the dress, the keyholes are relatively larger. Likewise they are smaller on the larger versions. This does not always make for the most aesthetically pleasing details on the far ends of the grade.

After all, a pattern designer designs a pattern to have the correct detail proportions for that prototype size. I think it is somewhat lazy for the pattern companies to then grade without changing all the proportions accordingly.

My shrinking/enlarging method using a ratio solves this grading proportion problem.

Okay, so are you ready to see how the mockup experiment works on a real person?

Here they are on me:

Side-by-side mockup comparison – actual 31, shrunken 34, and actual 34.

Obviously, the actual bust 34 size is too big for me:

Definitely too big.

When you zoom in to look at dart placement and where the armhole hits at the shoulder joint, you can really see which fits best.

31 (left) – dart too high, shoulder good.
Shrunken 34 (middle) – dart in the proper spot, shoulder good.
34 (right) – dart too low, shoulder too long (overhanging body).

All three had necklines that were a little too high for comfort. And both the 31 and the shrunken 34 had armholes that were a bit small (typical on vintage patterns). In the above photo, I have cut directly on the stitchline for all the armholes, but I have reshaped and cut on the corrected underarm curve for the shrunken 34.

Obviously, you can see that I have chosen to fit the shrunken 34 because of all the safety pins and drawn lines on the mockup. It had the least amount of alterations needed.

Shrunken size 34 pinned to fit.

I took in the side seams slightly, and pinned a test hem. I decided it needed a little more flare for the A-line skirt, which I added to the paper pattern when I transferred my pin markings to the pattern.

(Here’s an example of how I transferred fitting marks from another mockup to the paper pattern.)

Pattern altered based on mockup fitting. Probably too much flare added, but that is easier to remove than add in the end.

So what are your thoughts and ideas about my pattern scaling method? I would love to know if this works for others too! Please comment or send me photos or links if you try your own version of my experiment!

And in case you’re curious, here’s the geeky fabric I plan to use to make the real version of my dress.

Look! Batgirl! Oh, and Wonder Woman and Supergirl. But I’m mostly excited about Batgirl! =)


41 responses to “Pattern Sizing Experiment: Part 2 – Testing Three Mockups

  1. Bird and Bicycle July 10, 2013 at 11:14 pm

    So fascinating! All the built in ease really makes for a roomy garment! Love the details and your “shrinking” method of copying at 91%. Brilliant.

    • Brooke July 11, 2013 at 7:06 am

      Granted all that “ease” in the too big photo is because the pattern was the wrong size to begin with. I’ve seen lots of people sew things for themselves that end up looking like that because the garment is just generally too big for them – they don’t know that everything needs to be smaller. Something like that can be altered but it is a lot of work and definitely requires a mockup.

      Glad you enjoyed my experiment! =)

  2. Mary Kay Reynolds July 10, 2013 at 11:26 pm

    What size printer do you have? The copies look large. Do you have to tape them together from the printer? I have a lot of vintage patterns, so I should learn how to do this.

    • Brooke July 11, 2013 at 7:15 am

      I have a pretty standard sized HP inkjet printer. The copy/scanner bed surface is just slightly longer than a standard piece of printer paper (probably about 8.5″x11.5″). I just put my pattern on it in sections until I have all the areas of a piece copied and then tape them all together by overlapping the matching parts of a piece. (See the first photo in the post above.)

      If you don’t need to shrink or enlarge any of your patterns, tracing with tracing paper is a thousand times easier.

  3. Lorinda July 10, 2013 at 11:49 pm

    It is amazing how much better your ratio reduced pattern results are. I am going to have to do some math and expirements too. Thanks for sharing your results.

  4. Gjeometry July 11, 2013 at 2:05 am

    INTERESTING!!! Do you think the shrink ratio method works just as well for even larger sized patterns? I am the same size as you, and have some size 16 and 18 patterns I’d like to grade down. I also have several size 12’s that I think I may try this shrinking method. I have done this with Adobe patterns where the pattern was just not laid out properly and so in order to get it to fit on the paper, I sized it to ‘fit page’ instead of ‘actual size’ and when I compared the two, it appeared to have shrunk it down, proportionately. But, quite a minor difference, not like from a size 18 to a size 8.

    • Brooke July 11, 2013 at 7:23 am

      So far, I don’t think I’ve ever reduced or enlarged beyond 15% either way of the pattern I am copying on my printer. I’ve reduced one for myself from a size 36 bust (one size up from the above example) and it worked perfectly for darts. I have yet to try a pattern I have that is a 38 bust.

      I’m thinking I might need to try reducing even if the pattern is one size up – I recently made a mockup from a bust 32 pattern and it has quite a bit more alteration work than I want. Shrinking it might be the answer.

      The fit-to-page is exactly the same principle – and might be the solution if a pattern has a little too much ease. =)

  5. sweary sewer July 11, 2013 at 2:25 am

    so interesting. thanks so much for this post. 🙂

  6. carmencitabs July 11, 2013 at 2:35 am

    This is great info, keep it coming.

  7. Lizzie July 11, 2013 at 7:22 am

    My head is swimming from all the math and measuring! Your dedication to the perfect fit is amazing.

  8. sewlittletime July 11, 2013 at 7:56 am

    really good research! unfortunately i have to lengthen everything and often move the darts etc down so don’t think it would work for me – like you said, you have to be smaller in proportion! dixie dip did some really interesting stuff on pattern grading a while back, i think in relation to releasing her own patterns.

    • Brooke July 11, 2013 at 8:03 am

      You might still have good luck with it because it might eliminate some of the usual alterations on your list. Try enlarging from a smaller size pattern and see what happens. That has worked for me when sewing for larger kids. And I’d love to know what you find out if you do try it! =)

  9. Tia Dia July 11, 2013 at 9:13 am

    Love your geeky fabric! This is going to be a wonderful dress. I’ve been following your pattern shrinking, and it’s very very interesting reading. Whether or not I’d go to all this work for myself is another question, but it definitely takes a lot of the alteration work out of the project. Keep posting! I love learning, regardless of whether or not I actually incorporate the knowledge into what I do! 🙂

    • Brooke July 11, 2013 at 1:52 pm

      Thanks! I’m eager to cut my real fabric, but I’m debating the print placement, which is slowing me down, hehe.

      Normally, I don’t do three versions (because, yes, it is a lot of work). I usually just shrink something and it works when I make the mockup, so I go with it. I decided I wanted to see more of the details in order to determine why it works – thus, the three mockups for the experiment. Glad you found it interesting reading! =)

  10. sewexhausted July 11, 2013 at 12:09 pm

    Wow… This is great information! My middle daughter is tiny- and I am finding so many patterns have the smallest size at 8- I am finishing up a dress for her and it was HUGE- I had lots of fitting I had to do. I would love to try this and see how it works for her. I will have to backtrack and find part 1! ~Laurie

    • sewexhausted July 11, 2013 at 12:12 pm

      Oh and PS- love the super hero fabric. I have had plans to make a Batman dress – and some day it will happen. I have been a Batman fan forever- Batman was the FIRST word out of my mouth as a baby. (Thanks to my older brother)… I have a Batman lunch box I actually carry to work when I go… Batman is awesome… 🙂 (Batgirl ain’t to shabby either!)

      • Brooke July 11, 2013 at 1:57 pm

        Your daughter is probably about my size then – I have the same problem with so many patterns stopping a size too big. I hope my shrinking method works for fitting her too!

        The main reason I have a thing for Batgirl is because Yvonne Craig is my cousin. So I’ve liked Batgirl since I was a girl and my sister & I watched the ’60s tv show with her in it. =)

      • sewexhausted July 11, 2013 at 2:00 pm

        So cool… 🙂 the 60’s TV show was my intro to Batman and still my fave. We were allowed to watch one TV show a day when we were little and that was it for me! Secretly I still enjoy watching them… Batgirl is great in them too.

        I will definitely be trying this method then. It was interesting to see how the pattern companies are basically lazy and do not properly proportion some of the details. Tsk Tsk…

      • Brooke July 11, 2013 at 2:05 pm

        I was watching some of the old Batman episodes the other day and Barbara Gordon’s clothes! Oh my goodness, I need to copy some of them! It had been years since I had seen the show, and I never realized how cool her clothes were!

  11. Karen July 11, 2013 at 9:07 pm

    Well, this is really interesting! I knew immediately from the photos of your mock-ups that the shrunken 34 was the closest fit – and I never would have guessed that (I would have guessed the actual 31…) Your observations about the keyhole detail is also enlightening!

    • Brooke July 11, 2013 at 10:02 pm

      I’ve always seemed to have trouble with graded patterns because I’m all the way at one end of the size range. When I first started using my shrinking method, I wasn’t quite sure why it worked but never really looked closely at the reasons it did until now. I’m glad you found it interesting! =)

  12. missparayim July 11, 2013 at 9:25 pm

    Oh I love the supergirls fabric! I’m going to have to go back and read the background on this. It looks like a pretty good fit!

    • Brooke July 11, 2013 at 10:06 pm

      Thanks! I like that the fabric has a somewhat retro ’60s vibe with the colors in the print. So many superhero fabrics seem really modern and juvenile to me, so I was glad to find one I love.

  13. zibergirl July 12, 2013 at 6:35 pm

    What about enlarging a 34 to a 38 bust? What percent would you use on your printer for that? Just wondering if there is a mathematical scale that can be used. I love your experiment. It seems to work out very nicely.

    • Brooke July 12, 2013 at 7:07 pm

      Use the same ratio formula from Part 1, with the fraction 38/34. Treat the fraction as division – so 38 divided by 34. You get roughly 112% as your enlargement number. If you try it, please let me know how it goes! =)

  14. Sleven Smith July 15, 2013 at 10:02 pm

    What a darling dress! I love it! Having a quality pattern is very important when making a beautiful piece!

  15. Leila July 17, 2013 at 1:39 pm

    I always think about the details that don’t get graded right in patterns. I learned a lot from the 1912 group and it was that group, you included, that made me think about grading one piece and not just blindly grade everything at the same rate. Very cool post.

    • Brooke July 17, 2013 at 1:50 pm

      Thanks! I’m wondering if this ratio method might eliminate the need for so many FBAs. I know patterns are generally drafted for a B cup and when I shrink a pattern for myself, it seems more like the A cup sizing I need. So maybe enlarging would be like doing an FBA.

  16. Pella September 2, 2013 at 12:46 am

    Interesting experiment. I tried upscaling from half scale on my printer once but found it wasn’t accurate enough. What you say about the details, such as the keyhole shape, not always being re-thought in different sizes, is true, and one of the main reasons I’m not so keen on graded nests of sizes in patterns. Most of the major pattern companies have gone over to selling patterns like this, and many people like it because they feel they have several sizes for the price of one, but there is a downside.

    • Brooke September 2, 2013 at 5:25 pm

      Thanks for the comment! =)

      Yes, the upscaling of a half-scale pattern is not much different that using a pattern already scaled at 100% – it’s just a 1/2″= 1″ formula. Lots of period costume books print small scale patterns that can be enlarged to full size by referring to the “inch scale” marker printed next to the pieces. But if you use a ratio you can change that 1″ scale more appropriately for your body.

      And I agree, the more sizes in one envelope is definitely a better selling point to many people despite the fit downside. Most people just don’t know what they’re missing when it comes to good fit.

  17. Debbie Milton April 8, 2015 at 6:11 pm

    I found your website and tried this for a vintage pattern that had a 31″ bust and enlarged it for my 37″ bust. I cannot thank you enough! It turned out perfectly, and this technique has enabled me to buy vintage patterns i love that are “around” my size. Am a retired English teacher who now loves math! Thanks so much for all your time and effort in sharing this technique!

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