Showing posts with label Pattern makers. Show all posts
Showing posts with label Pattern makers. Show all posts

January 06, 2015

Book review : Sizing in clothing



This is one of the books I ran across while working on my own book on grading. Sizing in Clothing (Woodhead Publishing Series in Textiles) is a collection of scholarly papers edited by S. P. Ashdown on the current (as of 2007) issues related to sizing ready-to-wear clothing. It is a dense read and it took me every bit of time I had with the book to get through it. I'm glad I read it.

The audience for this book is very narrow in scope. This is not a book for someone starting their own apparel line. Do not run out and buy this book unless you have a real interest in sizing theory - it will not help you figure out the sizing for your line. If you did want to buy it, the book runs in the $200-$250 range. I obtained a copy through inter-library loan, which also proved a bit of a challenge. Only a handful of college libraries carry a copy they are willing to loan outside their library system. So I had to read this book on a deadline and handle the book with kid gloves over the holidays.

Some technical designers, pattern makers, and graders may be interested in some of the included articles. Over the next several weeks, I will post a review/discussion on some of the topics covered. My two favorite articles were on the History of sizing systems and ready-to-wear garments by Winifred Aldrich and Military Sizing. There are other really great topics about sizing and target markets, size standardization (a hot topic!), apparel production and sizing, and of course, pattern grading.

Because each chapter is written by different authors, it's hard to give a review of the book as a whole. Some articles were very well written and easy to read, such as my two favorites listed above. Others are written in a formal academic style which is very difficult to read and even more difficult to ferret out what the author is trying to say. As a collection, the articles cover nearly every angle.

Since the articles are written mostly by academics, there is a bit of a disconnect with those working on the front lines (the exception being the Military sizing article). It would be easy to characterize the writers as sitting in their academic ivory towers telling us what to do because they "know better". Embedded in many of the articles is criticism aimed at the industry for assumed sizing problems that the industry either "created" or refuse to solve. While some of the criticism is unfair in my opinion, the information they provide us is still valuable. I'll discuss some of this later in the individual reviews. Despite all of this, I'm glad there are people out there willing to think about these problems, propose solutions, and test them out.

December 15, 2009

Metric pattern cutting for children's wear and babywear - 4th Edition


Winifred Aldrich has released an updated edition of her pattern making book. Besides having a much nicer cover design, it reportedly contains a revised organization and emphasis on flat pattern making. I find this change interesting because more and more design entrepreneurs are utilizing flat pattern making today and this confirms my personal experiences in the industry.

From the abstract at Amazon:

Today’s popularity of easy-fitting styles and knitted fabrics means that basic ‘flat’ pattern cutting is used to construct the majority of children’s wear and babywear and this type of cutting is therefore emphasized in this new edition. Shaped blocks and garments, cut to fit the body form, are still included, and are placed in chapters covering some school uniform garments or more expensive fashion or formal clothes.

One primary difference between flat versus fitted pattern making is that the patterns have the same shape for the front and back pieces. For example, the armhole shaping is symmetrical. Creating patterns in this way results in a looser, more casual fit and it is appropriate for a lot of children's clothing. Even so, I see more of a modified flat method in actual use. Patterns are modified so that they aren't quite so boxy and more fitted. Yet, they retain some symmetry between front and back pieces.

October 26, 2009

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.

Two pattern pieces with seam allowances on

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

Comparing two pattern pieces to see if the cut edges match

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.

Comparing two pattern pieces with seam allowances off

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.

 Correcting the seam allowances so the stitching line matches

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.

Trimming seam allowances on a pattern piece for better matching

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

Two pattern pieces that match on the stitching and cutting lines