Do professional pattern makers work with seams on or off the pattern?

Professional apparel pattern makers work with seam allowances on their patterns nearly all the time. It's faster. I would argue it's more precise. This practice goes counter to what most pattern making classes teach. They teach that you must remove the seam allowances and add them back later. I don't know anyone in the industry that works this way. I think the idea is that working with seam allowances one can create variations that lead to fitting problems later. That's simply not true if you check your new pattern against the original block later. (This is assuming you make a copy or rubbing of your original before you start on a new style. But I'm sure you knew that).

If you are drafting by hand, it is time consuming to remove the seam allowances. Pattern blocks are made with seam allowances on. You would have to keep a set of blocks without seam allowances. It would be so easy to mix up seamed and unseamed pattern blocks. Apparel pattern makers leave their blocks seamed and theatre pattern makers or cutters leave their blocks (or rather slopers) unseamed. In fact a block is a finished pattern piece that includes all pattern markings and is seamed.

If you are drafting in CAD, you can turn the seam allowances on and off. You can work on the cutting line or the stitching line. It's a simple matter of hitting a few buttons. BUT, I have found that CAD programs have difficulty in calculating between seamed and unseamed because it involves a complex series of mathematics. So constantly switching between cutting and stitching lines can produce some weird anomalies. (As an aside, weird things can happen with notches on stitching versus cutting lines too). I have found this is true no matter which CAD system you use. So I work with seam allowances on and directly on the cutting line nearly 99% of the time. This means that I keep the seam allowances in mind while I work.

One Exception

In CAD, it is important to turn the seam allowances off and walk the pattern pieces along the stitching line in a few areas. Collars and necklines is one area that I nearly always check for matching on the stitching line. There are other situations that come up where this important. I learned this the hard way recently.

In this situation, I split a jacket back pattern piece and added corresponding seam allowances along the split line.

Next, I aligned the pattern pieces to make sure they match. At this point they did and I assumed all was right. Until I got complaints from the sewing machine operators that things weren't matching up. I had to go back and double check.

I took the seam allowances off the pattern pieces and realigned them. They didn't match, so I redrew the stitching line of the side piece to make sure it matched the center. I added back the seam allowances and realigned the edges.

 

The pieces didn't match again. Sewing machine operators also do not like this because they do not know how to align the pieces. In this particular case, the seam allowances are small, so I left the little "dog-ear". It can be difficult to cut those "dog-ears" off by hand when they are really small. It is easier to machine cut. In any event, there are different ways of dealing with this. I show one method below.

Your pattern pieces will then look like this and match up in every way possible.

Accounting for shrinkage and/or stretch in sewing patterns

Just a few comments I made in the Fashion Incubator forum when making patterns to accommodate stretch (knits, stretch wovens) and/or shrinkage.

Have to be careful when scaling patterns in CAD. Shrinkage/stretch is not proportionally the same in both directions. Many pattern making books advise to add the same amount of change to the length as the width. Don't do this. The only way to know is to know the fabric. Things shrink more in length than width. I am so sick of washing pants and long sleeve shirts and having them end up too short. If anything, remove width ease and add length on knits. It sounds counter-intuitive but prevents high-waters. Not sure on stretch denims, so test, test, test.

In my Etsy shop I have a simple tech pack kit that includes a wash testing form. The wash testing form includes instructions and formulas to figure out shrinkage in both the length and width of a fabric. It is well worth the investment of time and money to test your fabrics for shrinkage, particularly knit fabrics. Once you know the approximate shrinkage of a knit fabric, I recommend adding the extra width and length needed to accommodate expected shrinkage.

Adding a shrinkage allowance to a pattern piece may cause the finished garment to look proportionally wrong. If you do not pre-wash the finished item before shipping to the retailer, the item may look wrong on the hanger and the customer may decline purchasing the item because it does not appear to fit. So there is a limit to the amount of shrinkage you can include in a pattern before proportions, fit, and hanger appeal are impacted. Generally, you can include about 3-5% shrinkage in a pattern without too much of an impact. If your wash testing results return a shrinkage greater than 5%, then you either need to reject the fabric or pre-shrink the fabric before cutting and sewing.

Knits in particular add an added layer to product development because they are more likely to shrink. There are various types of knit fabrics with different types of finishing. Some knits are pre-shrunk at the factory and some are not depending on whether the fabric will be printed or dyed at a later date. When sourcing knits it is important to ask about shrinkage.

Accounting for stretch in knit fabrics is also another added layer. Stretch influences fit. Should the item fit close to the body? If so, the pattern needs to be reduced in width and length. This is another area where the amount to reduce will be different for the length and width. As an item is stretched in one direction, the other direction also changes. You may notice this when you stretch a knit t-shirt in the width direction - the length of the t-shirt will shorten. This is a complex topic and the answers depend entirely on the style and chosen fabric.

Design a clothing line with a plan

If you watch Project Runway or believe any of the stereotypical Fashion Designer drivel, you may think a line is designed by pure inspiration. A designer goes to a museum and is inspired by a piece of artwork and can magically create 5-7 pieces that all work together. Or perhaps a designer flips through some swatches and tosses some to an assistant to make samples out of. This kind of thinking is silly nonsense and will lead to disaster.

It is true that a designer can be inspired by a piece of artwork, a fabric print, color, etc. But unless one designs with a plan, or end goal, it will only be an exercise in design for design's sake. A design plan should follow some basic steps and answer basic questions:

1. Review the past line.
1. What sold best/worst?
2. Customer comments
3. Returns
2. Review past goals and set new ones.
1. Did you meet sales expectations?
2. What are my sales goals for this season?
3. How is my budget?
4. Set design budget for the next season.
3. Shop the market between seasons.
1. What are my competitors selling?
2. What are their price points?
3. Do I hang with them?

You'll notice that none of these questions have anything to do with design. They are ordinary business questions and it is good practice to review them at the end/start of a new season. Finally, I sit down and actually "design" my line.

1. Shop for fabric/trims. (this is where I find my "inspiration".
1. Does the fabric express the brand?
2. Does it fit within the price point for raw materials?
2. Determine number of styles/pieces.
1. Can any styles be carried over in new color/print?

I then sketch, come up with words to describe the group and generally get lost in the design process for about 2 days. I sample my styles directly in the real fabric. I don't do muslins or toiles - those are only to work out pattern problems. The sample making process can take a few weeks and gets a little nitty gritty, but at the end of the process you will have designed you line.

Tag Board for pattern making

I have needed to order tag board (manila folder paper for patterns) for a while. Up till now I haven't needed very much. My patterns are small and a large, heavy roll of the stuff seemed excessive. I think I have found a reasonable alternative until I need larger quantities.

I did a search for tag board among the big box office supply houses. Sure enough I found one that sold it in large pieces (24 x 36) in a box of 100 sheets. The pieces are big enough that I can cut out quite a few pieces at one time and still have left overs. I further economize by not cutting out square or rectangular pieces. Technically, every pattern piece should be cut out of tag board and if I were to send them to a contractor, I would. Square/Rectangular pieces are cut using cutting guides & charts. I have a cutting guide for sleeve cuffs and skirts indicating the dimensions for each size, for example.

Make a Design Storyboard

As I was designing Prairie Roses for Fall 2007, I created a digital design board. In school it was all about literally cutting and pasting paper onto illustration board. I like the digital version because it is much faster and more professional looking.


I had a hard time identifying and explaining the look I wanted. When I started it was simply a feeling. I decided a story board was the best way for me to explain my line to myself. I have rarely done this in the past - it always seemed like busy work. This time, I have convinced myself of it's necessity. As I struggled to find pictures that explained the mood, everything else seemed to fall into place. The words A Country Sensibility came to me and it was perfect for so many reasons. It made me think of Sense and Sensibility and Jane Austen - how can I translate Jane Austen's "look" into little girl's dresses. It made me think about sensible country living. Being grateful for what you have. Not living too extravagantly - but comfortably.

Anyway, I headed out with my camera and took pictures of the flowers growing in my flower beds and nearby scenery. There was my mood. I already had purchased the fabrics and they meshed perfectly. The red ombre ribbon roses were the highlight and the key to the brand name.

Prairie Roses was a difficult brand name to nail down. Do you know how hard it is to find a brand name that is not already in use? One that fits the mood and explains the look without the customer ever seeing the clothing? This is complicated by trying to find an internet domain name that is available. It took weeks of research.

The work required to pull all of this together had other benefits. I emailed a graphic designer a copy of my design board and she was able to design my logo (which is shown on the right). I am fairly pleased with the results of the line, the logo, the brand. It all meshed together so perfectly. It feels good to be focused and I am excited about designing more for this line.

Next week is even better. I have been working on toddler patterns and I have a fitting/photo shoot scheduled. I am excited!

A boy's shirt pattern fix for Butterick 6030 pt. 2

A boy's shirt pattern fix for Butterick 6030 pt.1 is here

Well I spent a few hours working on this pattern and sewed up a sample. I decided to go ahead and do a style similar to the original. My sample is a basic shirt with a convertible collar. Once the patterns are completely worked out, endless style variations can be developed. So far I have corrected:

• Neckline smaller
• Reduced and reshaped front self-facing
• Reduced seam allowances. 1/4" s.a. for the neckline, 3/8" everywhere else.
• Drafted a new collar - a one piece collar that folds in half.

I thought it might be useful for my readers to see how I construct a simple, casual shirt. This is not a finely tailored shirt, by any means - just the basics to test the pattern. These steps are production-style but allow for use of home sewing machines. At this point, I assume the pieces have been cut and markings and notches have been transferred. BTW, I reduced the number of notches and only used two drill holes (could use chalk) for the pocket placement. Also, you'll notice I did not use any interfacing. Interfacing is often eliminated in children's clothing from budget to high-end clothing. Firmly woven fabrics may not need any stiffening. During product development test and see if you really need it.

1. Prep work - edge finish the the pocket edges and long edges of facing. Fold collar in half and stitch collar ends (called "close" in the industry). Sew shoulder seams.


2. Details. Turn and press collar. Use a pocket template and press pocket. Stitch pocket hem. Topstitch pocket to left shirt front. Edgestitch collar. I think collars look best edgestitched 1/8" from edge. Further away can look homemade - but depends on style.


3. Attach collar. This looks more complex than it is. This fabric is hard to see but there are three notches on the collar. Two match up with the shoulder seam and one for the center back neck match-up points. Sandwich the collar between the front facing and neck (notches on shirt front indicate center front neck where collar starts and and another for the fold back of facing). Clip the top collar at the shoulder seam point a little less than the seam allowance depth 1/4". Stitch the collar on using a 1/4" seam allowance, flip the seam allowance of the top collar out of the way. Notice there is no grading and clipping (my least favorite thing to do).


Tomorrow I'll show how to finish the collar, attach sleeves and give a review of the results.

Big Box Technical Designers

Several years ago (was it really that long ago), I learned a very important lesson. I was working on a private label program for a Big Box retailer, company X. The technical specs they sent us were fairly straight forward. There were a few wonky measurements, but we forced our samples to spec.

As a patternmaker/pseudo tech designer, working on a private label program for a large account, I worked under the assumption that the BIG company knew what it was doing. Their specs were gospel and they could not be adjusted. You meet spec or you risk losing the account. This was true for another private label program for company Y. However, company Y's specs were superior (in other words they worked out of the box).

With any private label program, you take a selected sample and adjust the patterns to meet spec. You re-sew the sample in production fabric and submit it to the company's technical design department. The technical designers will go over every measurment and construction detail. They have the power to cancel the order if you don't meet spec. Usually, the first sample is rejected and you have to submit a second with corrections. (This is especially true if this if the first time on a new private label program). Needless to say, there is a lot of pressure to meet spec the first or second time. There is a lot riding on these samples.

So we submit our sample (with forced spec conformity) to company X. We received back our audit reports with required corrections. The weird thing was that the technical designers changed some of the required specs (now some were really wonky) and they insisted on construction/pattern changes. The construction/pattern changes would have affected several things, especially allocations and labor costs. Private label programs operate on slim margins, and our in-house manufacturer would not agree to the changes. The measurement issues didn't make sense, proportionally.

What to do? Here was a high dollar order and we wouldn't be able to meet spec. The only way to solve the problem was to call the technical designer at Company X and explain the situation. I expected them to reply, "Meet spec or we cancel the order."

To my surprise, the technical designers agreed to allow some of our measurments and construction details to pass. I don't think I explained too much. It was more like, "It would be easier for us to do things this way."

I learned something very valuable that day. If something isn't working, present an alternative - it just might be acceptable. I also learned that the technical designers for Big Box retailers don't know everything.

The reason this experience came back to me is because I am facing a similar situation, except I am the technical designer on the other end. As part of my consulting, I am helping to develop a new style in China. It is a difficult style, so I expected the first samples to have a few problems. Unfortunately, the samples had more than a few problems (some minor, some not). I wish the Chinese factory understood that it would be ok to present an alternative. I could see they struggled to meet my spec, so they forced it (and didn't really succeed). Not sure how this will be resolved....