pattern grading

If you read last week’s post on grading a pattern up and understood the concepts behind it, then let me tell you: grading a pattern down in size is really, really easy! Once you have grading up under your belt, down is literally just the opposite procedure! Begin by tracing the pattern pieces as before, being sure to include that horizontal line for matching purposes.

You’ll follow the same dividing line principles as I outlined in the previous post. But instead of cutting apart and spreading the pieces, you’ll be overlapping them to reduce the width of the piece (thus, grading down). How do we do this?

Once you have marked those dividing lines on your pattern pieces, draw lines parallel to indicate how much the sections need to overlap. The math we did last week still works for grading down, and so we’ll stick with our example grade (4″ overall) for continuity. The red lines on the diagram above indicate the dividing lines, and the blue shows were the sections will overlap.

Now the next step just depends on your own preference: you can either fold the pattern piece or cut and overlap the pieces. I tend to do the latter, especially on larger pieces. Once you’ve either folded or cut and overlapped your pieces, you’re done grading down!

To overlap, begin folding along one line (in this case, the red one), creasing that edge. Fold it back up and over, creasing the second line (blue) so it is under the original fold. This subtracts the total amount (3/8″ for our example) from the pattern. Continue with the remaining lines.

For the slash and overlap method, begin by cutting along one of the lines (red). Overlap that cut edge over the other, to meet the second line (blue) to take up the grading amount (3/8″ for the example). Make sure the horizontal match line is even and secure in place with a bit of tape.

Again, you will need to true the edges and smooth out the cut edges as well as any darts that were disrupted during grading.

Wasn’t that easy? The “rules” for grading in general apply to both grading up and down, so once you’ve understood the one you can easily do the other. I’ve included a couple more dividing diagrams below for other pattern styles. { click here to continue reading this post }

June 29, 2012 · 19 lovely thoughts
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Welcome to part two of this series! In this post I’ll be covering the basics of grading up–or enlarging a pattern. This is perhaps the most often requested, since a lot of vintage patterns in smaller sizes survive. But if you need to grade down, then never fear–that is the next installment!

One thing I want to say before I get started is that this is my own method for pattern grading and this is by no means comprehensive. If you want to learn more indepth methods to grading, there are a lot of textbooks available that I’m sure get into more nitty gritty details and techniques than I have time to cover. But for grading up a few sizes, this is a good option for the home sewist.

That brings me to another thing I want to point out: this is a method that is best suited to grading up a few sizes at a time. Any more than 3 sizes, and you risk distorting the pattern edges. If you need to go from say a vintage size 10 (30″ bust) to a vintage size 20 (40″ bust), I’d suggest grading first up to a size 14 (34″ bust) and then to a size 20. Trust me: the larger the gaps between the pieces, the greater the risk you accidentally loose the edge integrity and throw off placement for things like darts. (Don’t forget you’ll also need to lengthen the pieces during the grading process, which I’ve touched on at the end.)

Final point (and then we’ll get started, I promise!): As I said in my previous post, grading does not negate the need for a fitting muslin. Grading is simply enlarging (or reducing) the pattern. It does not magically make it fit your body perfectly (unless, of course, you are one of those lucky people who can fit a pattern straight out of the envelope–how I envy you! hehe!). So grade, make a muslin, and fit. ‘Nuff said.

Begin by tracing your pattern–I never cut my original pattern to grade (especially vintage patterns), as I want to keep the original intact. I went over what I use in the previous post for tracing my patterns. Essentially, I lay the piece on my cardboard cutting mat (I usually iron it gently and on the lowest, non-steam setting first), and the transparent paper over top. I trace all the edges, markings and grainlines. Be sure to label each piece too! Cut them out once they’re traced.

For the example pattern, I’m going to say that we’re grading from a 32″ bust/24″ waist/34″ hip to a 36″ bust–a 4″ difference. We’re going to be doing an even grade (I’ll go over some of the basics of uneven grading later on in the series), so the overall grade will be 4″ resulting in a 36″ bust/28″ waist/38″ hip. Here’s where you’ll need to do a little math!

Take that grading measurement–4″–and divide by 2. This measurement (in the example it’s 2″) is what we’ll grade over the entire 1/2 of the pattern. (Meaning that most patterns have a half bodice front, half bodice back, etc.–it’s essentially half a dress!) Since we have a front and back piece for the bodice, we’ll divide this 2″ by 1/2 again to reach 1″. This 1″ is the total grade for the front or back. (So when you have graded your pieces and make a complete bodice, it’ll have been graded 4″ overall.)

We’re almost done with the math! Take that 1″ and divide it by 3. I never divide evenly, since it gets a little cumbersome. Generally I’ll do a 3/8″-1/4″-3/8″ division for a 1″ grade. You’ll see where these measurements go below. Write this down somewhere, since you’ll use this on each front and back piece to reach that overall 4″ grade.

This is the pattern I’ll be using as an example for the instructional portion of this post. It’s fairly simple, and I feel showcases the basic principles of pattern grading the best. Scroll to the bottom for a few more schematics of other pattern types too!

One thing I almost always do on pattern tracings prior to diving them (otherwise referred to as “slash and spread”) is make a horizontal line across the pattern. Your pattern may already have this in the form of a lengthen/shorten line, but if not, it’s a good idea to draw one now as it helps match things up once you’ve cut the pattern apart.

This shows the basic dividing lines for most bodice patterns: from neckline to waist, shoulder to waist, and underarm to waist. Note on the back pattern piece rather than going straight from the armhole down, I angled the line. This is because a straight line would have ended above the waist, which we also want to grade up. Note I also tend to avoid cutting in the middle of a waistline dart. Of course, your pattern will probably vary–but once you know the basics of where to place your lines, you’re set. I have rarely deviated from this configuration in the years I’ve been grading by hand–usually it works for the majority of styles.

To go along with our example grade (4″ increase overall), these bodice pieces have been cut along those dividing lines and spread the appropriate amount we calculated above. I tend to spread less over the shoulder to waist slash. Why? Because adding too much to that area tends to give a pattern “linebacker shoulders”. If you have to do a Full Bust Adjustment, wait to do that until after you’ve graded the pattern–don’t try to “cheat” and add it at this point!

This is how I usually set up my cutting board while I slash and spread the pattern pieces: a piece of paper underneath, and the graded piece (slashed and spread) pinned overtop. I tend to just retrace the entire piece. But you can also tape additional paper underneath if that’s easier. It really just depends on the size of the grade!

The last thing you need to do after you grade the pattern, as you’re tracing (or after you’ve taped in other paper), is to true the edges of the pattern as they’ve probably gotten a bit jagged with all this grading! This just means to connect with a smooth line one point to another as above in red (on the front piece). Cut out your new pattern piece (if you’ve traced, making sure you’ve transferred all darts, grainlines, etc.) and you’re done!

For more grading examples, click the “more” link below. { click here to continue reading this post }

June 22, 2012 · 76 lovely thoughts
posted in sewing,tutorials · tags: , ,

A common question I find in my inbox is “how to I alter the size of a pattern?”. If you’ve read this blog for any length of time I’m sure you’ve seen me discuss the idea of pattern grading. But what is pattern grading, if you’ve never run across it before (or maybe you have and it’s still just a somewhat confusing concept)? Grading is a method of sizing a pattern up or down in size. This can be done manually using paper and rulers, or is now often done on computer programs (most often by the larger companies, since these systems can be pricy for the home sewist). Because you aren’t tied to the size on an envelope, this is an especially useful skill to have if you work with vintage patterns. But it’s a good tool to have in your sewer’s bag of tricks period, as it has many uses.

Throughout this series I’ll be going over both common and basic grading techniques, as well as breaking down how to grade some more complicated styles. We’ll be using the old fashioned, paper method, since that is most available to everyone. It is my hope that this series will be a clear overview of basic grading to get you started. I’d like to be upfront and say that this is not going to be hugely comprehensive (there are textbooks for that), nor do I know every grading technique. I have been grading using this method for the past 10 years, and have picked up some tips through study and developed my own ways of approaching it. But I feel that for the home sewist, this is perhaps the easiest method to grasp.

Please note this is not a sew along—it’s just a series. You do not have to follow along as I post these (though you are welcome to!), but can refer to them in the future when needed. These posts are rather spread out because they are time intensive to put together, and I want to give myself enough time to give them some polish and cover as comprehensively as I can (within reason) the topic.

  • Paper – I use exam table paper, since it’s both transparent and cheap. This is the most important part of grading: having transparent paper. Because you’ll be tracing your original pattern, it makes life a lot easier. Another option is to use a non-fusible, lightweight interfacing (such as the gridded interfacing sold at JoAnns). Or you could use Swedish Tracing Paper. Though because of the cost I don’t recommend that for the actual grading, but perhaps tracing your final, master pattern on to. The bonus of using this is you can also pin it together to create a sort of fitting muslin (though it does not drape quite like fabric). In a pinch, large sheets of tracing paper can be used. From personal experience: don’t try tissue paper, it will only end in tears.
  • Rulers – A variety of rulers and measuring tools is always handy for grading patterns. I generally rely on my gridded ruler (2” wide by 18” long with markings every 1/8”–commonly found in the quilting section of fabric stores) for the actual grading. A ruler that goes into even smaller increments (1/16”) would be handy too. I also keep a hip curve and yardstick on hand for tracing patterns.
  • Pens, Pencils, Markers – Fairly self-explanatory. Sometimes I find having fine-tip markers in a few colors useful when differentiating between grading lines.
  • Scotch Tape – A must for adding extra paper underneath when grading up, or overlapping when grading down. You’ll go through a lot of this, so be prepared! (I like clear tape only because you can see through it. You can use opaque tape, but it’s a personal preference.)
  • Cutting Surface – I use my trusty cardboard cutting mat, but a self-healing mat will also work. I tend to pin the pieces I cut apart into my cutting surface in order to keep them from wandering/moving. So this isn’t a must, but makes it easier.
  • Pins – Just regular, straight pins (as I referenced above, I pin the pieces into my cardboard mat).
  • Your Measurements – Having a sense of what size category you fall into is very useful when grading for yourself. (Admittedly, I tend to “cheat” on this and just grade to the pattern size that I know I fit into, and then make my personal fitting alterations. Generally I’ll be assuming you are doing the same for the majority of the series, until I get into uneven grading in the July 6 post.)

I want to note here that while grading is a wonderful, highly useful skill, it does not take away for the need to further fit your pattern to your own body or making a muslin for some more complicated designs. As with anything that involves alteration, I always recommend double checking the fit before cutting into your garment fabric.

That sums up the supply list and next we’ll be moving on to actual grading! I plan on not only showing you through photographs, but a series of illustrations as well. Grading up a pattern size is perhaps the most common request I receive, so that will be first (with grading down following shortly behind—it’s a very similar technique though!). My hope is that by sharing this technique with you, it’ll open a whole new world of sewing skills and possibilities!

June 6, 2012 · 52 lovely thoughts
posted in sewing · tags: , ,