Introduction & Overview

Reading a Flat

Pattern-makers are able to recognize the following information in Technical Flats:

  • darts
  • dart equivalents (gathers, pleats, tucks)
  • design lines
  • information about added fullness and contouring
  • information about garment parts such as pockets and collars, and
  • details such as stitching and notions.

However, the patternmaker will also be given a Specification sheet which has a lot more information on it. For example, the flat may show that a skirt has flare, but it cannot tell you exactly how many inches the hem width is.  The specification sheet will give this information.

Firstly we will look at how to recognize some important information in the Flat, in later pages we will look at how this information is applied to make patterns.

Of course we (the home-sewer-patternmaker) will need to draw our own design, make our own specification sheet and draw our own flat, so we need to draw something that we can read.

Note that Flats are usually not colored; in my examples I do use color.


First note the difference between a dart on a flat, two-dimensional Block or Pattern, and a dart on a Technical Flat, which is a three dimensional representation of the flat block/pattern – see Figure 1.

Recognizing Darts

Darts are lines that end somewhere inside the flat, they do NOT cross from side to side.   In Figure 2, note the difference between darts (left) and a style line (right).

Darts can be curved

Darts do not have to be straight lines, in Figure 3 below the two Flats are basically the same – they both have two darts except one has straight dart lines, the other curved.

Stylelines or Design Lines

Stylelines or design-lines cross the flat from seam-line to seam-line, and the line designates separation; i.e. difference pattern pieces.  In Figure 4, the  bodice flat on the left (blue) has only one pattern piece.  The flat on the right would require two pattern pieces (the side pieces are the same pattern piece).

Often, but not always, darts are in incorporated into design lines.  In Figure 5 both of these style lines have the full value of the bodice darts incorporated into the design line.

In Figure 6, the design line (shown by a pink line) in the left (purple) flat does not have any dart involvement, while the yoke in the yellow flat may or may not incorporate an armhole gape dart.

Dart Equivalents

Dart equivalents include gathers, pleats and tucks, as in Figure 7 below.  (Style-lines are also Dart Equivalents)

Added Fullness

Generally Added Fullness with be indicated by gathers, flares, pleats and tucks.  In the industry, while the Flat will to some extent give an indication of the amount of fullness that needs to be added,  this will often be determined by the specification sheet.  If making your own patterns, you might draw something with flares/gathers, but you will need to do some testing to see exactly how much fullness to add in order to get the look you want.  Looking at shop purchased garments can be very useful for this; for example, measure the skirt hem width of different dresses/skirts that you like, and see what kind of fullness you need to achieve certain looks. 

Note the comparison in Figure 7 where gathers, pleats and tucks indicate dart equivalents, and Figure 8 they indicate Added Fullness (as well as dart equivalents, as there are no darts).


When armholes are cutaway and/or necklines are lowered, contouring will be required.  The patternmaker will know what changes to make to the block to make the garment fit better in the armhole and neckline.  

The line of the basic pattern goes from the neckline over the bust and down to the waist.  As you can see in Figure 9, there can be a lot of space in between the fabric and the chest and the fabric under  the bust and the torso.  (Image the white tape is the fabric line).  This means when creating garments with low necklines (for example), adjustments need to be made so that the garment doesn’t gape in the neck.

Patternmakers know when contouring is required and how to made the necessary adjustments.

You will need to read and understand the section on Contouring to know when contouring applies and how to make the changes to create the pattern.

Parts of Garments

Parts of garments include collars, sleeves, pockets, plackets, etc.  These are fairly easy to recognize on the flat, and all the detail for them will be noted in the Specification Sheet.

A professional patternmaker would have learned over time how to to make these garment parts; e.g. how much to overlap the blocks at the shoulder when making collars, etc.   This would be a case of learning on the job and referring to textbooks.   In some cases, for example creating a puffed sleeve, it is just a case of applying a principle (Added Fullness), but in other cases it is not so obvious.  Again, a patternmaker learns this over time.

For the home-sewer-patternmaker, creating the garment parts are not so obvious the first time around.  Armed with the knowledge of manipulating darts, adding fullness and contouring doesn’t necessarily give you all the knowledge you need to create things like shawl collars, etc.  That means while you are learning to make patterns and you want to make a design with a different collar or sleeve (etc), you will need to look up how to best make those garment parts.  While you could in some cases work this out by yourself, the problem is that you don’t know what you don’t know… and you may not end up with an ideal sleeve/pocket/collar.  There are some things that you learn over time, doing it again and again.  The same applies for anything that you learn.

Stitching & Notions

Fashion flats will contain detail such as stitches, ruffles, lace, buttons, rivets, sequins, fur trim, zippers, belt loops etc.  They can include intricate detail, for example for a zipper they will show the zipper stop, slide, pull tape and teeth.  If you are a home sewer and can’t draw at all, this level of detail isn’t needed for your technical drawing.  However, you should note these items down on the flat in writing if nothing else.  Never assume that you will remember in a week what you were thinking of today; write everything down.

In the next page we will look in a bit more detail at Dart Equivalences.

3 Responses

  1. Hi,
    I have a question.
    In Figure 6, you say the design line in the left (purple) flat does not have any dart involvement. Could you pls help me understand this further? maybe any other website link you could share so that I understand what you mean.
    I mean if you aren’t calling it a dart then how is it a style line?
    In figure 5 (pink) you say the full dart has been incorporated into the style line.

  2. Hello Madhubani

    When I say the design line on the purple top in Figure 6 does not have any dart involvement, I am talking about the line at the neck (see attachment – the pink lines are the design lines I am using in the example – not the waist darts or the side seam darts).

    A design line is just line. To use a different example; if you want to add a 2-inch panel at the bottom of a skirt to add contrasting fabric – you draw a line and separate the two pieces. When you add in a design line like this, all you need to do is add seam allowance on both sides of the line.

    In a similar way, the design line on the left in Figure 6 is just a line. The garment is separated and seam allowance is added – there is no dart involvement.

    The yellow top on the right has a design line right across the body. This line may not may not have some dart value incorporated into it – for example if there was a gape dart in the armhole, rather than move it to the side seam darts, you could put it into this design line.

  3. Got you now.
    I was thinking of the waist dart in the purple image and not the style line on the neck, hence the confusion.

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