Drafting a Basic Bodice Block – Explained

In this post I want to cover the methodology and the process involved in drafting a basic fitted bodice block. By breaking the process down into steps, and explaining the reason for taking those steps, I hope I can give you a better understanding of the process.

This is a complex post, and for my readers that are not ready for this amount of detail, I promise some beginners content at the weekend!

As I have discussed in earlier posts, drafting instructions rarely explain the steps they take and the quantities they suddenly add on. Hopefully here some of those mysteries can be solved!

Here we go…

The drafting notes below refer to my size 12 UK or 8 USA dress stand, The measurements supplied are in centimetres and the inch conversion is in brackets after. The general instructions are the same for whatever size you are drafting.

One more point that is worth mentioning is that there is little point in drafting any pattern or block unless you have an accurate size chart to refer to (you can find one in my subscribers bonus content area). Even if you are taking measurements from a client you will still need to refer to a size chart as a guide and also as a safeguard to ensure the measurements you have are not too far from the expected, if they are, then you should know why. For example drafting for a very large bust and your client knows her bust is large for her skeletal frame.

Step 1 – Rectangle Width

Let’s start with a rectangle; the width of the rectangle will be half your bust measurement and also half the ease you would like in the block. Why half? We are working on half the body.

You may also question why you need to incorporate ease. It is important to note that even if you would like a tight fitting block, it is always advisable to add in some ease in to a basic block and then take it out via pattern cutting methods as you develop the style later. The normal expected ease over the bust level for a basic bodice block is 7.5 to 10cm (3 to 4 inches).

Mark in point 0 and point 1 as illustrated on the plan below

Step 2 – Rectangle depth The depth of the square will be the nape to waist measurement plus a 1.5 cm (9/16”) allowance for the neck shaping at CB (Center Back). Complete the rectangle as shown, marking a line approximately 10 cm (3 15/16”) out from a point 1.5 cm (9/16”)  down from O. Mark in point 2.

Mark in the CF and CB and waist guide line.

Step 3 – Marking the Scye Line

Mark point 3 down from 0 as the total armhole depth (18 cm (7 1/16”) for a size 12UK (8 USA) with a 0.6 mm (1/4”) grade per size) plus 3.8 to 4 cm (ease), 3.8 (1 ½”) for a slightly tighter armhole and 4 (1 9/16”) for a little more room. Square a line out at 90 degrees to the CB to touch the CF, Mark this as line 3. For my size 12 draft I placed this point 22 cm (8 11/16”) down from 0. This line is known as the scye line.

Step 4 – Dropping the Center Front Line

Mark point 4 between 1 to 1.5 cm (3/8 – 9/16 Inches) down from bottom right corner of the rectangle (CF Line) – drop this point for each additional size above a size 12 UK (8 USA).

Let’s look a little closer at this for the different sizes you may draft.

Step 5 Locating the Side Seam

Mark point 5 half way along line 3, drop a straight line down from point 5, parallel to CF and CB and drop this point 1 cm (3/8”) below the waist guide line this point increases or decreases by 0.3cm (1/8”) per size change – call this point 5a.

Step 6 – The cross back line

The cross back line is an important line to mark on your basic block, this is the line of greatest prominence and also where the back is at its widest. The back shoulder dart cannot travel below this line and the back waist dart cannot travel above.

The cross back line is situated half way between the back neck guide line and the scye line (line 3) square out from the center-back – square out half your across back line measurement plus 1 extra cm (3/8”) ease for now, there will be more ease added when you draw in the armhole

Step 7 – completing the back neck line and also the front neckline shaping

For the back neckline planning we will use proportion. There are many different ways to plan a back neckline and it all depends on the fit you prefer, remember this is a basic block and adaptations can be made later during the pattern making process to amend fit. The back neck depth should be a minimum of 1.5 cm (9/16”) deep, and can also be calculated as a proportion of the neck base girth. The neck base girth for my set of measurements is 36 cm (14 1/8 inches).

Front neckline shaping. The width of the front neckline is the same as the back. The depth of the neckline is equivalent to the neck base girth divided by 6 plus 2 to 3 cm (13/16 to 1 3/16 inches) ease Plan the neckline as shown, mark a point 1.25 cm  (½ ” ) at the corner and use as a guideline to shape a gentle curve.

Step 8 – The armhole

Again the armhole is planned using proportions.  Now double check you have added 1 cm (3/8”) extra onto the end of your half cross back line measurement at the cross back line, square up and down from the end of this line – up to touch the top of your rectangle and down to touch the scye line. Where this line touches the skye line mark this as point A.

Point B is measured up from A and is the armhole girth plus 2.5 cm (1 inch) / 6

Point C is measured up from B and is the armhole girth plus 2.5 cm (1 inch) / 4

A1 from point A is the armhole width (Scye width)

B1 and C1 are parallel to B and C – now you have another rectangle to work in.

Now drop point C1 by 0.5 cm (3/16”)

Continue to swing arcs from A through C and from A1 through the point newly created by dropping C1.

The back shoulder measurement will be your intended finished shoulder measurement, plus 1.5 cm (9/16”) for a back shoulder dart (if you want one) and some extra allowance for ease.

On the arc you have created for through C you will touch your required shoulder measurement, with the extra for the dart, plus a little ease, between 0.4cm (3/16”) and 1 cm (3/8”) ease is advised, so in this case I will add 0.4 mm (3/16”) ease to each shoulder line measurement as I like my shoulder line to sit right on the shoulder and not go much past the shoulder point. I have added 1.5 cm (9/16”) for a shoulder blade dart too.

Mark the back shoulder line first.

Step 9 – Planning the bust dart width

We need to plan the front bust dart width first before we mark in the front shoulder so leave the shoulder area for now.

Most bodice drafts you find in pattern cutting books draft to a B cup, sometimes a C. If you have that cup size then that’s great, however many of us don’t, myself included.

If you are a different cup size then you can go with the 1/20^th proportion as explained below, and this involves you finding 1/20^th of your full bust measurement. If you have a smaller bust cup than a B then this should work well for you and you can avoid having to make a small bust adjustment to the block after the drafting process.

If you have a very large cup size you may find that this alone is not enough and you will need to make a full bust adjustment to the block after the initial draft, and I will be explaining how to do this in a later post.

Measure across from the neckline your chosen dart width, I selected to place 1/20^th of the total bust measurement I am using (90.5 cm divided by 20 = 4.5cm)

Now draw in the shoulder line and as you did with the back, make the measurement you require hit the arc you swung through the lowered C1. The measurement for the front shoulder is the measurement for the back shoulder minus the 1.5 cm (9/16”) you added for the shoulder blade dart (if you added one)

Now plan the front and back armhole shaping, making a right angle at the shoulder point and touching the 2.5 cm (1 inch) points in the lower corners of the rectangle.

STEP 10

BUST LEVEL AND SUPPRESSION

If you are drafting to an individual’s body measurements it is worth taking a little time at this point to assess where the bust level is and the bust point, while it is difficult to plan on a flat draft with great accuracy, you should at least have an idea of your intended wearers general figure type, if they are a little older and have a lower bust level, this can be planned for now to avoid huge fitting problems at your block fitting. Remember to assess the bust level when your client is wearing a well-fitting bra and standing straight up. When marking point 6 on the draft it is also worth checking the clients bust point to bust point measurement and making any adjustments. Please see my information on bust fitting to address any bust fitting issues now, if you know you are drafting for a client who has problems achieving a good fit in this area then this extra time considering the fit will be very worthwhile.

If you are drafting to a size chart or to a lady who has a B cup fitting or even an A or C cup then you can proceed with the general drafting instructions and make minor adjustments on the figure or dress stand.

Here is a general guideline to bust width – i/e bust point to bust point measurement – IT DOES ALSO VERY MUCH DEPEND ON THE BRA YOU ARE WEARING TOO!

We are now at a stage where we need to add in the suppression and the bust level.

As a guide, find the central point along the Bust line between point A1 and the Center Front.

Mark a guide point there. This is where the bust point on a regular block would be measured from, but it is not necessarily where your wearers intended bust point should be measured from; however we can use this as a starting point and make any adjustments we need.

Now mark in the bust point (BP) and the remaining dart leg for the bust dart (sometimes called strap dart, although I don’t like that!)

Step 11 – completing the suppression

We now need to complete the suppression at the waist and also add a small shoulder blade dart.

Let’s look at the waist, measure your wearer’s waist and then decide how much ease you would like to add in to the waistline. The waist for this size is 70.4 cm (27 ¾”) and I will add 7 cm (2 ¾”) ease – so half waist plus half ease

35.2 cm (13 7/8”) +3.5cm (1 3/8”) = 38.7 (15 ¼”) – The draft waist measures 50.2cm (19 ¾”)

50.2cm  (19 ¾”) – (minus) 38.7 (15 ¼”) = 11.5cm (4 ½”) – This means 11.5 cm (4 ½”)  needs to be taken out in the form of darts at the waist level

Place the larger portion of suppression in the front block this figure should be around 5 cm (2 inches) for a size 12

Place between 2 and 3 cm (13/16 – 1 3/16”) at the side seam and the rest at the back waist. Use your judgement to adjust the proportions accordingly as the sizes you draft change.

Marking in the waist darts

Drop a line from the bust point and extend this line by 1.8 cm (11/16”) below the waist level guide

Swing an ark from the BP through the end of this line and mark 2.75 cm (1 1/16”) each side of this central line on the arc, mark in the dart legs.

Do the same for the side seam dart, applying half the finished dart width each side of the side seam.

For the back dart measure along the scye line to point A – divide this measurement in 2 and add 1 cm (3/8”) extra, towards the side seam. Mark a point on the scye line. Drop a line parallel to CB and extend this line 0.5 cm (3/16”) below the waist guide. Mark in the dart as instructed previously.

The only thing left to do now is to mark in the back shoulder blade dart. We allowed 1.5 cm (9/16”) for this dart.

Extend a line from the apex of the back waist dart; straight up to the cross back line.

Find the center of the shoulder and mark a point, connect this point to the line you have just connected to the cross back line.

Mark half the total shoulder blade dart each side of this point 1.5 cm (9/16”) divided in 2 is 0.75 cm (5/16”) each side. Connect these points back to the cross back line and the waist dart line.

If you would like to shorten the shoulder blade dart, then feel free to shorten it as needed.

Now shape the waist line with gentle curves to join the dart legs.

Now trace the block and fold in the darts as you cut the block out to make the correct shaping at the dart mouth. Or see my post on shaping darts correctly to do this without having to cut out!

 Here is a measurement chart that is useful to fill in with your measurements before you begin the drafting process. I always find this helps speed things up when I am drafting to a new set of measurements.

F