Tuesday, 6 December 2016

Craftsy Class 1: Constructing & Fitting a Bra

These notes are taken from my latest Craftsy course, Bra making Fit and Construction, with Beverly Johnson. I chose to make the same bra that is featured in the course, the Pinup Girls Classic Full Band Bra. Note that seam allowances are ¼" throughout, typical for bra making.

Lesson 1: Fitting and Fabric

  • Take your high bust and full bust measurements and round up to the nearest even number. For me, that was 42 and 46". My band size is therefore a size 42. My cup size is the difference between the two measurements (4") which correlates to a letter of the alphabet - 1" = A, 2"' = B etc so 4" = D cup. The underwire should be longer than you need and the same as the band size i.e. 42". I ordered WL42 along with the kit from Sew Squirrel online.
  • DOGS = Direction/amount Of Greatest Stretch. May not be same as grainline.
  • Band fabric - always good to have spandex in it for a little extra recovery. Aim 25 - 40% stretch measuring 10" in an inch or two from the edge of the fabric. Examples of band fabric include: (1) Techsheen (a type of power net) and (2) mesh.
  • Frame fabric - you never want to have spandex in it, too much stretch. Aim < 20% stretch. Examples of frame fabric include (1) Duoplex (can use shiny or matte side), which is similar to tricot, has 5 - 10% stretch (2) Simplex, (3) a stable lace, and (4) woven fabric cut on the bias. Also sheer cup lining ('Marquisette') is extremely rigid, good for frames and bridge, and doesn't fray. Ironically, not so good for cups as doesn't 'mould'.
  • When looking for bra making fabric you are most concerned the movement of the fabric. Movement refers to both stretch, which means the fabric contains Spandex fibers (also known as Lycra and elastane), and give, which means there is mechanical movement of the fabric based on its weave or knit.
    The fabric for the bra cups should have little to no movement to contain and provide shape to the breasts. When you look for cup fabric think smooth, thin and strong because you want support and you want your clothing to move freely over the bra. You also want a fabric that is comfortable and washable.
    Typical bra cup fabric fibers are nylon, polyester, cotton, Spandex and silk. Bra fabrics are usually a tricot, raschel or even jersey knit. Woven fabrics like stretch silk charmeuse (silk with Spandex) are used for luxury lingerie, as is 100% silk, used on the bias. 15 Denier is too soft for larger cups. Bra tulle can be used for bra cups, either singly with lace over the top or double with the stretch in opposite directions.
    The bridge and frame also need to be made in a low to no movement fabric to keep the cups in the correct place on the body. Generally the same material that is used for the cups is used for these parts of the bra along with a stable lining for the bridge.
  • Lining fabric is used to stabilize the bridge of the bra. Lining can also be used in the fabric manipulation process to create a more stable fabric.
    When you start shopping for bra making linings you will see the term “denier”. Simply put, denier is a measure of the density of the weave of the fabric. The lower the number, the more sheer and lightweight the fabric.
    There is no need to line Duoplex but when I do line bra cups, the lining I like to use is a 15 denier nylon with 25% crosswise and 0% lengthwise movement (pictured at the bottom right in the image above). There are also nylon “sheer cup” linings with virtually no movement that I like to use for the bridge (the swatches pictured in the top row above).To manipulate a fabric to make it have low to no movement properties you can double it, line it, fuse it to a tricot interfacing or bond it to another fabric using fusible weft. If you are not sure how to go about manipulating your fabric, no worries! I will take you through the different fabric manipulation approaches in an upcoming post. Once you know how to adapt fabrics for bra making, it opens up a whole new world of possibilities!
  • If you want to steer clear of manipulating your fabric for now but want to use something other than Duoplex, I have had good results using bias cut silk, bias cut Liberty Tana Lawn and even a double layer of stretch charmeuse for the Marlborough. Remember to test any fabric changes in the muslin process before you sew up your final bra.
My definition of layering is treating two layers of fabric as one throughout the construction process but allowing the layers to remain independent from one another in the final bra. Examples of layering include putting a stretch lace or mesh over a tricot or over a power net (both pictured below) or even doubling the fashion fabric itself. The easiest way to connect two layers of fabric together for easier handling during construction is to use a dissolvable spray adhesive (you can find my resource list here). Adhere the base fabric to the upper layer in a large rectangle, and then cut the desired pattern pieces from the “new” fabric you created. Just be sure that the direction of greatest movement in the overlay fabric matches up with that of the base layer and that it is smooth and flat on top of the base fabric. This approach works well when you have a delicate open work overlay such as a stretch mesh or where there is no other option for beefing up your fabric such as in the band. Layering is not a great option if your fabric is already beefy (like swimwear Lycra weight) because the fabric combination will end up being too bulky for a bra.
Lining is closely related to layering, the difference being that the layers are constructed independently. This approach is primarily used when you want to line a cup that is made out of a fraying fabric such as silk. In that case, you want all the seam allowances to be enclosed and concealed. This means that two separate sets of cups are constructed. Like layering, lining does not work well if the fabric has any bulk.
Bonding fabric means permanently adhering two layers of fabric together. Bonding has quickly become my favorite fabric manipulation option. It allows me to convert Spandex prints into a suitable bra making fabric and allows me to create my own fabrics by layering laces on top of colored tricots. It has the added benefit of making the pieces incredibly easy to handle during the construction process and limits any potential puckering or bagginess that can occur when working with two layers of fabric.
There are two ways to bond fabric. One is to bond a fabric to a fusible tricot interfacing. The other is to use a fusible web between two layers of fabric.
Lightweight tricot interfacing, pictured below, is often used for knits. It has some crosswise movement and little lengthwise movement making it a suitable bra making material on its own. The non-fusible side is also smooth against the body, as you would expect from a tricot.
Block fusing is the easiest way to bond fabric. This means taking pieces of interfacing and fabric, that are large enough to accommodate your pattern pieces, fusing the two together and then cutting the pattern pieces out of the new fabric you created. In this process you will want to be sure to match the direction of greatest movement in your fabric and interfacing.
 drawback of using tricot interfacing is that it is only available in black and white so if your fabric does not look good with either as a base, you will need to find another option. You can see from the above picture, where the lower right half of the spandex print has been fused to a white tricot interfacing, that it does alter the appearance of the fabric. I should also mention that tricot interfacing does not make a good base for open work fabrics. Something about the look of the interfacing where the fusible has melted is not really suitable for the right side of the garment.
That brings us to the second bonding approach – fusible web (a.k.a. MistyFuse). Once I found fusible web, I felt like I had discovered bra making magic.
Fusible web, pictured below, looks like a fine cobweb and is correspondingly very lightweight. It comes either with paper on one side or plain as pictured below. It has the wonderful property of disappearing as it melts to combine two layers of fabric, even when you bond an open work lace to a tricot fabric.
To use fusible web, use the same block fusing approach described above with one important change: use a non-stick surface such as parchment paper or a Teflon pressing sheet above and below the fusing area to prevent the web from sticking to your ironing board or iron. Note that if you use parchment paper on the right side of an open work fabric, you will get more of a matte finish than if you use a Teflon pressing cloth.
Bonding with either fusible can also be used in another way: to create your own tricot bonded foam to use for making bra cups. Just bond tricot fabric or tricot interfacing to both sides of a thin batting and you have a sheet of cut-and-sew foam. You can read more about sewing bra cups with foam in my article in Threads magazine, Issue #174 (subscription required).
While bonding has many benefits, it also has one big limitation; it cannot be used for the band of the bra because of the stretch demand in that area. Layering is the only manipulation option you can use to make a band firmer.

Lesson 2: Getting Started

  • Mark the DOGS on each piece of fabric then pin the pattern pieces to the fabrics with arrows parallel to the DOGS.
  • Use a small rotary cutter (18mm is best) to cut out the pieces - you could draw around the pieces first for greater accuracy.
  • Use a washable marker to mark the notches - don't snip, the SAs are only ¼" and are too prone to getting cut into.
  • Add stickers to the right sides of the fabric pieces.
  • Staytape the neckline and underarm area of the upper cups from strap to wireline, using either twill tape (can be bulky) or a strip of tricot (= duoplex) - use a shorter stitch length and sew with ⅛" seam so it remains invisible after the elastic/straps have been sewn in place.
  • Sew upper cup to lower cup at internal seam line with absolutely no stretching, from point to point, with just a pin at either end. Stitch using an edge stitch foot in ¼" seam with the lower cup on top (helps prevent the seam from stretching out) and a stitch length of 2.5. Make sure not to stretch the upper layer as you sew.
  • Press cup seams open over a newell knob screwed onto a piece of wood with lots of steam. Topstitch both sides of the cup seam with a 3.5 stitch length at 1/16", pulling the seam apart as you go. Trim the SAs back to the stitching line using Pelican scissors.
  • Sew the straps to the upper cups, the square end of the strap to the cup not the tapered end, so that the straps lie pointing away from the midline. Press the strap seams closed and up towards strap. Topstitch 2 lines of stitching on the strap, at 1/16" and ⅛"
  • Sew the back band to the band frame, matching seam lines. Press SAs towards front frame and topstitch with 2 lines.
  • Sew the cups to the band, sewing with the band on top and only 2 pins.
  • Mark ½" down from the CF and 1" down from the underarm, on the cup.
  • Cut channeling pieces 2" longer than underwire. Press the underwire channeling into a half-circle curve using steam. Sew channeling to upper side of cup SA only (use a wider size of channeling for larger cup sizes), lining up the edges of the channeling with the seam line and not using pins. The aim is to sew exactly on the seamline. Only sew the channeling up to the ½" mark from the neck edge of the cup and to the 1" mark down from the side of the cups. The channeling will extend either end.
  • Turn the channeling toward the band side of the bra, away from the cup, and edge stitch close to the seam line from the right side, making sure to pull fabric away from the seam line so no pleats form.

Lesson 3: Sewing the Elastic

Bottom band elastic

  •  Choose ½ - 3/4" width elastic with little stretch - plush side goes next to the body. Measure the length of the lower frame/band and cut elastic to length.
  • Mark the band with a washable marker at the following points: under each cup where the curve changes at either side ( = total of 4 marks).
  • With RS together sew elastic to bra band - picot edge towards the body of the bra - using a zig-zag stitch (L = 2, W = 2.5). Sew right next to the picot edge with no stretch of the elastic until the first mark. Needle down. Between marks, stretch elastic by ½", stitch to mark making sure to keep the (curved) edges even.
  • Between the cups, clip the band fabric at ½" intervals so that the curved edge of the band lies flat. Stitch to next mark. Needle down, stretch elastic by ½", stitch to next mark. Stitch to the end. When the bra is laid out, the lower curve of the frame/band should be gentle not wavy. Trim the band SA.
  • Turn elastic to inside and stitch on opposite edge of elastic edge using a 3-step zig zag (L = 1, W = 5). Sew from inside, manipulating the curves under the bust and keeping the channeling out of the way.

Side elastic

  • Choose 5/16" or 3/8" wide elastic.
  • Sew elastic along the outside of strap (not stretched), along the side of the cup (stretched by 1" - make sure to hold the fabric either side of the needle so the needle doesn't break), and along the back band (slightly stretched) using a zig zag (L = 2, W = 2.5). Sew with RS together and picot towards the strap. Flip elastic to the inside, trim the strap SA and sew near picot edge using 3-step zig zag (L = 1, W = 4).

Neckline Trim

  • Pin tails of channeling down, out of the way.
  • Pin the cup SAs towards the bridge CF
  • Stitch the neckline trim runs down the inside edge of the strap (not stretched), across the top of the cup (not stretched), across the bridge (not stretched) and back up, with RS together using a zig zag (L = 2, W = 2.5) and keeping the stitching on the elastic (outer) part of the trim. 
  • Insert the underwire with the low end toward CF and bar tack in place.
  • Bar Tacks

    • Bar tacks stop the underwire from pushing out of the channeling.
    • On inside, at CF, fold neckline trim down and lay both channels on top of the trim. Mark upper and lower edge of trim on channeling. On lower line, straight stitch across and back (L = 1), then zig zag across and back (L = 0.8, W = 1.5), on the channeling only.
    • Cut channeling off at upper mark so that the ends will fit under the neckline trim.
    • Sew other side of neckline trim (not stretched) using a 3-step zig zag (L = 1, W = 4)  making sure the channeling follows the cup seam and the ends are tucked under, using 1 pin at the CF. The bar tack should lie along the lower edge of the neckline trim.
    • On the inside, stitch the other side of the channeling in place, making sure there is enough room for the underwire.

Lesson 4: Finishing the back band

Applying the strap elastic

  • Strap elastic is available in 3/8- 1" widths with fancy edges, a satin face and a plush back. Sliders and rings should be the same size as the elastic width.
  • Cut 10" of the elastic and push one end up through the slider, over the centre bar and down the other side, forming a short ½" tail. Stitch from the RS using a short straight stitch and zipper foot, across and back twice (= 4 rows).
  • Slide ring onto strap with WS up. Take tail and pass up through slider, over centre bar and down the other side, leaving a long tail.
  • Check that the width of the back band is the same size as the hook and eye closure and if not, trim to fit.
  • Pin the strap to the lower curve of the band on RS. Lie the straight edge of the strap elastic up with the straight edge of the band then straighten the fabric to fit the straight elastic even though there might be pleats formed and pin. Stitch on the inside edge to top of bra band, form 2 steps across top, then stitch down middle of strap, and 2 steps across the bottom, using a lightning stitch.
  • Thread fabric strap though ring, from front to back, and pin in place. Stitch in place with straight stitch, across and back, twice.

Attaching the hooks and eyes

  • Note that the LHS of the band has the eyes.
  • Clean up the back band edge.
  • Insert band into raw edge of eye band. Stitch across the end of the band, turn, take 2 steps, sew across to the other end, turn and take 2 steps back to the beginning.
  • For the hook band, insert in the same way as for eyes, or, if there is no prefinished pouch for the hooks but instead a flap, fold flap down and under bra band and stitch in place from hook side using a straight stitch and zipper foot to get close to hooks.

Lesson 5: Fitting

There should be no large vertical pleats under the strap area (= cups too big)
There should be no overflow at the top of the bra or underneath (= cups too small)
Bra band should be snug and not ride up at the back (=band too big)
Straps shouldn't move outwards or pull bra up at the front (= straps too short)

Straps wrong length

  • If the straps are too long or too short, cut off/add on 2" to the square end of the strap pattern.
  • Note that straps sitting too far in or too far out is a cup issue, not a strap issue.

Band wrong length

  • Slice the band pattern vertically and add or subtract width. Make sure to true the top line again from furthest points which don't change.
  • If the straps are sitting too far out, move their position on the back band by elongating the top line of the back band towards CB by ½ - 3/4". Redraw the curve from lower scoop point to the newly drawn point.

Side seam fit

  • Check the fit of the side seams, particularly for any excess around the side seam line. If there is excess, eg can pinch out an inch at the top of the side seam, you may need a dart.
  • To do this, on pattern alter both front frame and back band at the side seam area. Draw a line from ½" in from top of the frame side seam almost to the lower corner (forming a hinge) and move the flap across eg ½" and tape in place. Do the same to the bra band side seam. Redraw the top line between the side seam point and the top point.

Bottom band

  • If the bottom band rolls at the side or there is a horizontal pleat, usually at about ½ - 3/4" up from the side seam.
  • Lie the frame and band pattern pieces together, matching side seam lines (draw them in). Mark a point ½" up the side seam on both frame and band. Draw a curved lower line from the mark down towards the centre of the cup on the frame and towards the bra back on the band.
  • Redraw the short end of the bra band back to form a 90o angle.

Altering the bridge

  • The bridge can be too wide (feels like the wires pressing on the breast tissue so need to trim ⅛" from CF fold on pattern) or too narrow (feels like wires and cups are pulling apart so need to add ⅛" to CF fold on pattern).
  • If the bridge is okay at the top but too narrow or wide at the bottom of the bridge (eg a gap forming under the CF if the bridge is too wide), you may need to add a dart. Draw a line from CF corner at the top of the bridge almost to lower edge, ¼" in from CF (forming a hinge) and move flap in the desired amount. Make the lower edge and top edge 90o. Do the opposite if the bridge is too narrow at the lower edge. Draw in new DOGS line parallel to new line.

Front strap position

  • On the upper cup pattern, draw a line from the outer, lower side point of the strap area across to 1" before the edge of the pattern, parallel to the DOGS line, and up to the top of the pattern. Cut along the line and move whole piece e.g. ½" towards CF or CB. True the line from lower point of strap to lower point of cup, the points that don't move.

CF neckline is baggy

  • If the CF neckline is baggy a dart can be taken out of the upper cup eg ¼".  To do this, cut almost from ½" in on top right of upper cup to the lower right point, forming a hinge. Overlap the hinge pattern piece over the larger left pattern piece by eg ¼" and tape in place.
  • Re-cruve the top line from the known points ie the top right point of the upper cup over to the top left point near the strap, using a French Curve. Trim off the excess pattern.
  • If the neckline is too tight, do the opposite.

Rounding the crown

  • Tape the lower cup to a piece of paper and mark ⅛" at the CC mark. Redraw curve to the left of the mark. Add an amount equal to that taken away, to the other side of the cup. Walk the upper cup seam line around the new lower cup seam line, either side of the CC notch, and redraw as necessary to make seam line lengths match.

Lower cup flattening

  • If the volume of the lower cup is rounder than the fabric, a flattened area will appear just above the underwire. This can be eliminated by splitting the lower cup and building in extra room.
  • On the lower cup, draw a line from the CC point to point A. Cut along the line, separate and tape each pattern piece (inner lower cup and outer lower cup) to paper. Draw a line from top and bottom corner of each pattern piece using a French curve that adds ⅛" at middle between marks. Use the same numbers on the French Curve to add to both pattern pieces. Add ¼" SA. Add a notch towards the top of one new line and transfer exactly to the other by tracing it.
  • Alter the DOGS on each pattern piece. On the inner lower cup piece draw a line form ~ ⅓ of the way along the lower seam line (from the newly notched line) to the apex. Note that this will be nothing like the old DOGS line; it aims to push the breast. Turn the pattern piece over and trace DOGS onto the outer lower cup pattern piece.

Lesson 6: Bra embellishment

  • Add rigid lace or embroidered tulle to the bra, considering mirroring or at least balancing the pattern.
  • Cut the lace the same shape as the upper cup top and sides but let the lower edge fall over the cup seam. Glue in place with a Uhu stick while the pattern pieces are flat, construct the cup seam and then attach the free edge of the lace.
  • To attach the free edge of the lace (usually scalloped), use a wide zig zag and a lighter pressor foot pressure

1 comment:

  1. Hello Helen near Sydney,
    like your notes about bra making, useful, thanks.