Developing A Simple Bra Pattern from Basic Bodice Block
1D Developing A Simple Bra Pattern from Basic Bodice Block http://localhost/techniques/developing-a-simple-bra-pattern-from-basic-bodice-block
Using a custom fitted Basic Bodice Block constructed previously, a detailed, step-by-step explanation of how to create a bra pattern is presented. The overall idea is that if you have your own bodice block, by following these steps you will be able to construct a custom-fitted bra pattern. References : 1) Ann Hagar, Pattern Cutting for Lingerie, Beachwear and Leisurewear, 2nd ed., Blackwell Publishing: Oxford, 2004, 279 pp. 2) Winifred Aldrich, Metric Pattern Cutting for Women’s Wear, 5th ed., Blackwell Publishing: Oxford, 2008, 215 pp. N.B. An additional method for determining the size of the darts has been introduced as of March 5th. Step 1
2S This is a basic blouse block, custom constructed for a woman with a 36 inch bust, 35 inch chest, 32 inch waist, a 14 inch nape to waist measurement, and an 8.5 inch waist to hip measurement. The bodice block (the term used for this kind of pre-pattern template) shown does not include the waist darts. Details on constructing a basic bodice block from an arbitrary set of measurements will be provided in a second "How To" - this one used the process described in the Aldrich book given as a reference. Step 2
In order to proceed to the next step, the front dart needs to be moved - this is done by cutting along the line indicated, rotating the triangle of paper and retaping it to the other edge. Also, the block must be cut down the middle of the three dashed lines, and the two pieces slid across each other (they will hence overlap in the middle), so that the total bust measurement from CB to CF is the exact bust measurement measured from the body (that is, the ease that was introduced in the process of creating the basic bodice block is being removed!). Note that for both this diagram and the previous one (and all subsequent ones), no seam allowances are shown. The two horizontal lines are the waist line and the bust line. Step 3
3S The result of these operations is shown in this Figure 3 - note the narrowing of the armhole and the shifted dart on the right (front section of the blouse). A new centre line has been redrawn half way between the previous edges when overlapped. Step 4
4S There are two ways of introducing appropriately sized darts.
Method #1 : Two waist darts are added before the "basic bra block" is drawn in. The width of the basic waist darts are determined by the difference in measurement between the bust measurement and the waist measurement, divided by two (because the basic block is only half the garment), and then divided by three (there are three waist darts, the two shown and one in the middle that is lost in the overlapped region). For the purposes of the bra construction, the width of both the waist darts and the front bodice dart are doubled, so as to create a raised "cup" shape for the breast.
Method #2 : A somewhat more accurate way of estimating the dart sizes is by using an "overbust" and an "underbust" measurement, in addition to the bust measurement itself. The width of the dart along the top line of the bra form is determined by half the difference between the overbust and the bust, while the width of the front dart along the bottom of the bra form is half the difference between the bust and the underbust measurement, minus the small dart width associated with the back dart (width about 2.5 cm or 1" at the waist level). Shown also are the side seam located at the central line (B-G), and the "forward front seam" which is to the right of the side seam and tilted forward at the bottom.
The upper edge of the basic bra block is constructed by marking the left edge at Centre Back (CB) 1.5 cm above the bust line (point A), marking the central seam 2.5 cm above the bust line (point B), marking each side of the bust dart a distance of 9.0 cm from the bust point (points C and D - note that the lines shown follow the doubled dart size, not the dart shown), and marking the rightmost edge 2.5 cm above the bustline (at Centre Front CF, point E). The points A-B-C-D-E are then connected by lines. For small sizes, reduce each of these measurements by 0.3 cm, while for plus sizes, add 0.5 cm to each measurement. The lower edge of the basic bra block is constructed by marking the leftmost edge (point F) 2 cm below the bustline, the side seam (point G) 4.5 cm below the bustline, the two sides of the front waist dart (points H and I) at a distance of 7.5 cm from the bustpoint (BP), and the rightmost edge 2.5 cm below the bustline (point J at CF). The points F-G-H-I-J are then connected by straight lines. As for the upper edge, the distances are reduced by 0.3 cm for small sizes and increased by 0.5 cm for plus sizes. Step 5
5S The next step will be to cut out the basic bra block as drawn here. At this time the back bra strap will be bent forward to remove the dart shown. This could be done at a later step as well, it is simply convenient to get this manipulation out of the way now. Step 6
6S The cut shape of the basic bra block is shown overlaid onto the bodice block. Note that the straps have also been cut and placed where the would connect to the bra block. Step 7
Next, we shall cut along the bustline from the CF edge (rightmost edge) to the bust point (BP in Figure 4), and rotate the two sections created to eliminate the upper and lower darts, taping across these seams. This converts the vertical dart to a horizontal dart. Step 8
7S In addition to switching the vertical darts for a horizontal one, we have also drawn a circular shape (hemisphere) through the lower piece and cut along this line. The circular section begins 1 cm (2/5") forward of the top of the forward front seam. This is a design choice - from the basic bra pattern shown in the previous step, several possible variations in bra design are possible. In this example, we are developing a design that gives a fair amount of support to the breast without, however, using an underwire. Note that this results in four pieces - the back strap, the lower cup, the upper cup and the frontspiece. Step 9
8S To increase the clarity, we get rid of the background bodice block, which has started to make things confusing. Step 10
9S The next step is the result of another design choice, and could be done differently. The pattern produced by the previous step could have been finalized per se. In this step, we improve the support offered the breast by raising the lower cup slightly. The increase may range from about 0.5 to 1.5 cm, depending on the amount of additional support desired. I have chose to raise the cup by 0.5 cm - the new shape of the lower cup is shown drawn in. The upper cup must be reduced by a similar amount, resulting in the curved lower edge shown drawn in. In addition, however, by adding curvature to the upper seam of the lower section and reducing the curvature of the lower seam of the upper section, we have an unbalanced seam length. To correct for this, the upper section is cut along the dart direction and spread to reintroduce the necessary width. Step 11
In this intermediate diagram, the change to the upper section is shown, while the change to the lower section has not yet been introduced. Note that the frontspiece has been modified in this version, by squaring off the top and rounding the bottom part (this is easier to do if the piece is unfolded into its right and left halves, as shown here). Step 12
0S The final step introduced yet another design choice to enhance support for the breast, by increasing slightly the fabric that sits under the cup. The frontspiece is reconnected back to the back strap. In this final step, the upper seam is changed to introduce a strap again, the shaping at the back is changed for a more streamlined design, and the bra pattern is separated at the side seam. Step 13
1S This is the final result of all these manipulations. The CF fold has been restored, and the locations of notches to help match the pieces during sewing has been introduced. Step 14
The final pattern generated by the process. I have introduced a 1 cm seam allowance (the seam allowance is small because for lingerie you don't want to have to deal with a lot of fabric bulk in your seams), and added in the notches. The strip is 3/4" (2 cm) wide, that is, double its final width. This pattern is to scale at 1:4 - that is, enlarge it four times and it will be an exact fit for the original pattern. remove
Developing A Simple Bra Pattern from Basic Bodice Block
Using a custom fitted Basic Bodice Block constructed previously, a detailed, step-by-step explanation of how to create a bra pattern is presented. The overall idea is that if you have your own bodice block, by following these steps you will be able to construct a custom-fitted bra pattern. References : 1) Ann Hagar, Pattern Cutting for Lingerie, Beachwear and Leisurewear, 2nd ed., Blackwell Publishing: Oxford, 2004, 279 pp. 2) Winifred Aldrich, Metric Pattern Cutting for Women’s Wear, 5th ed., Blackwell Publishing: Oxford, 2008, 215 pp. N.B. An additional method for determining the size of the darts has been introduced as of March 5th. Step 1
2S This is a basic blouse block, custom constructed for a woman with a 36 inch bust, 35 inch chest, 32 inch waist, a 14 inch nape to waist measurement, and an 8.5 inch waist to hip measurement. The bodice block (the term used for this kind of pre-pattern template) shown does not include the waist darts. Details on constructing a basic bodice block from an arbitrary set of measurements will be provided in a second "How To" - this one used the process described in the Aldrich book given as a reference. Step 2
In order to proceed to the next step, the front dart needs to be moved - this is done by cutting along the line indicated, rotating the triangle of paper and retaping it to the other edge. Also, the block must be cut down the middle of the three dashed lines, and the two pieces slid across each other (they will hence overlap in the middle), so that the total bust measurement from CB to CF is the exact bust measurement measured from the body (that is, the ease that was introduced in the process of creating the basic bodice block is being removed!). Note that for both this diagram and the previous one (and all subsequent ones), no seam allowances are shown. The two horizontal lines are the waist line and the bust line. Step 3
3S The result of these operations is shown in this Figure 3 - note the narrowing of the armhole and the shifted dart on the right (front section of the blouse). A new centre line has been redrawn half way between the previous edges when overlapped. Step 4
4S There are two ways of introducing appropriately sized darts.
Method #1 : Two waist darts are added before the "basic bra block" is drawn in. The width of the basic waist darts are determined by the difference in measurement between the bust measurement and the waist measurement, divided by two (because the basic block is only half the garment), and then divided by three (there are three waist darts, the two shown and one in the middle that is lost in the overlapped region). For the purposes of the bra construction, the width of both the waist darts and the front bodice dart are doubled, so as to create a raised "cup" shape for the breast.
Method #2 : A somewhat more accurate way of estimating the dart sizes is by using an "overbust" and an "underbust" measurement, in addition to the bust measurement itself. The width of the dart along the top line of the bra form is determined by half the difference between the overbust and the bust, while the width of the front dart along the bottom of the bra form is half the difference between the bust and the underbust measurement, minus the small dart width associated with the back dart (width about 2.5 cm or 1" at the waist level). Shown also are the side seam located at the central line (B-G), and the "forward front seam" which is to the right of the side seam and tilted forward at the bottom.
The upper edge of the basic bra block is constructed by marking the left edge at Centre Back (CB) 1.5 cm above the bust line (point A), marking the central seam 2.5 cm above the bust line (point B), marking each side of the bust dart a distance of 9.0 cm from the bust point (points C and D - note that the lines shown follow the doubled dart size, not the dart shown), and marking the rightmost edge 2.5 cm above the bustline (at Centre Front CF, point E). The points A-B-C-D-E are then connected by lines. For small sizes, reduce each of these measurements by 0.3 cm, while for plus sizes, add 0.5 cm to each measurement. The lower edge of the basic bra block is constructed by marking the leftmost edge (point F) 2 cm below the bustline, the side seam (point G) 4.5 cm below the bustline, the two sides of the front waist dart (points H and I) at a distance of 7.5 cm from the bustpoint (BP), and the rightmost edge 2.5 cm below the bustline (point J at CF). The points F-G-H-I-J are then connected by straight lines. As for the upper edge, the distances are reduced by 0.3 cm for small sizes and increased by 0.5 cm for plus sizes. Step 5
5S The next step will be to cut out the basic bra block as drawn here. At this time the back bra strap will be bent forward to remove the dart shown. This could be done at a later step as well, it is simply convenient to get this manipulation out of the way now. Step 6
6S The cut shape of the basic bra block is shown overlaid onto the bodice block. Note that the straps have also been cut and placed where the would connect to the bra block. Step 7
Next, we shall cut along the bustline from the CF edge (rightmost edge) to the bust point (BP in Figure 4), and rotate the two sections created to eliminate the upper and lower darts, taping across these seams. This converts the vertical dart to a horizontal dart. Step 8
7S In addition to switching the vertical darts for a horizontal one, we have also drawn a circular shape (hemisphere) through the lower piece and cut along this line. The circular section begins 1 cm (2/5") forward of the top of the forward front seam. This is a design choice - from the basic bra pattern shown in the previous step, several possible variations in bra design are possible. In this example, we are developing a design that gives a fair amount of support to the breast without, however, using an underwire. Note that this results in four pieces - the back strap, the lower cup, the upper cup and the frontspiece. Step 9
8S To increase the clarity, we get rid of the background bodice block, which has started to make things confusing. Step 10
9S The next step is the result of another design choice, and could be done differently. The pattern produced by the previous step could have been finalized per se. In this step, we improve the support offered the breast by raising the lower cup slightly. The increase may range from about 0.5 to 1.5 cm, depending on the amount of additional support desired. I have chose to raise the cup by 0.5 cm - the new shape of the lower cup is shown drawn in. The upper cup must be reduced by a similar amount, resulting in the curved lower edge shown drawn in. In addition, however, by adding curvature to the upper seam of the lower section and reducing the curvature of the lower seam of the upper section, we have an unbalanced seam length. To correct for this, the upper section is cut along the dart direction and spread to reintroduce the necessary width. Step 11
In this intermediate diagram, the change to the upper section is shown, while the change to the lower section has not yet been introduced. Note that the frontspiece has been modified in this version, by squaring off the top and rounding the bottom part (this is easier to do if the piece is unfolded into its right and left halves, as shown here). Step 12
0S The final step introduced yet another design choice to enhance support for the breast, by increasing slightly the fabric that sits under the cup. The frontspiece is reconnected back to the back strap. In this final step, the upper seam is changed to introduce a strap again, the shaping at the back is changed for a more streamlined design, and the bra pattern is separated at the side seam. Step 13
1S This is the final result of all these manipulations. The CF fold has been restored, and the locations of notches to help match the pieces during sewing has been introduced. Step 14
The final pattern generated by the process. I have introduced a 1 cm seam allowance (the seam allowance is small because for lingerie you don't want to have to deal with a lot of fabric bulk in your seams), and added in the notches. The strip is 3/4" (2 cm) wide, that is, double its final width. This pattern is to scale at 1:4 - that is, enlarge it four times and it will be an exact fit for the original pattern. remove
Developing A Simple Bra Pattern from Basic Bodice Block
