Tuesday, August 9, 2011

Boys Trunks - changing the fit

How everybody likes their undies to fit is a pretty personal thing, so in this post I am going to show you some ways that you can alter my free Boys Trunks Pattern to get the fit that you want.

For a looser fit in the legs

Slash the main pattern piece through the leg, up to the crotch stitching line, as shown in the photograph below.  Spread the pattern piece the desired amount.  Smooth out the leg opening curve when you are cutting.

For a looser fit in the crotch

Take the crotch pattern piece and make two slashes, from the centre front through to the stitching line on the other side, in the bottom half of the crotch piece.  Spread the desired amount.  Again, smooth the curves when cutting out.

 For a closer fit in the crotch

Slash the crotch pattern piece as shown in the photograph for a looser fit.  Then, instead of spreading the pattern pieces apart, you overlap them the desired amount.

To change the rise (height of the waistband elastic)

For this, you will need to make alterations to both the main pattern piece and the crotch pattern piece.  Sit the crotch piece on top of the main piece, so that the sewing lines (not the cutting lines) are sitting on top of each other and there is a smooth line at the top of the pattern piece.

You can either cut the top of the pattern pieces, to make a lower rise, or add some height to the pieces to get closer to the waist.  You do not have to remove / add an even amount all the way across.  In the photograph below, I have lowered the rise at the front of the pattern, but left the back rise as it is.  This is shown by the pink line on the pattern pieces.  Just make sure that the back line is at right-angles to the centre back fold line (CB) and the front part of the line is at right angles to the centre front (CF) seam on the crotch piece.
 Separate the 2 pieces and cut on the line.
If you change the waistband position, you may need to change the elastic length.  Just make the trunks up until it is time to add the elastic,  Try them on and measure the length of elastic that you need.

Sunday, August 7, 2011

Boys Trunks Pattern

Related posts:
Trunks tutorial
Changing the fit of trunks

Okay, so this is the first time that I have tried to share pdf files from a blog, so for sure there is a better way!  This is how I have worked out how to do it for now.  I have uploaded the pattern files to Scribd.  I think you have to login into Scribd to download the files.  It does not cost anything to sign up to Scribd.

There are 3 pages to this pattern. Each page is given in a separate pdf file.  Click on "Download" at the bottom of each picture.  The downloaded file can then be opened and printed from Adobe Reader.  I created the files to be printed on A4 paper.  I'm not sure what happens when you print on letter paper, but each page does include a bit of overlap, so hopefully that works okay as well.

If you scroll past the 3 pictures, you will find pattern info, including a size chart and notions list.

Boys Trunks Page 1

Boys Trunks Page 2

Boys Trunks Page 3

Size Chart

Size Hip Measurement Elastic measurement Hip Measurement Elastic measurement
(cm) (cm) (inches) (inches)
3 57.4 52.6 22 5/8 20 3/4
4 60 54.9 23 5/8 21 5/8
5 62.6 57.2 24 5/8 22 1/2
6 65.2 59.5 25 5/8 23 3/8
7 67.8 61.8 26 3/4 24 1/4
8 70.4 64.0 27 3/4 25 1/4
9 73 66.3 28 3/4 26 1/8
10 75 68.1 29 1/2 26 3/4

Fabric Selection: this pattern is designed for knit fabrics with good stretch and recovery.  Cotton-lycra, supplex-lycra or viscose-lycra blends would be ideal.
Supplies and notions

  • 0.4 m of fabric (this should be enough to make 2 - 3 pairs, depending on the size)
  • soft elastic, 20 - 25 mm width, see table for length
  • polyester thread
  • stretch or ball point sewing machine needle 
Pattern Info

Seam and hem allowances are included with the pattern.   Seam allowances = 6 mm (1/4").  Hem allowance is 10 mm (3/8").

Thursday, August 4, 2011

Boys Trunks Tutorial

For this tutorial, I have chosen fabric that looks different on the right and wrong sides.  The right side is a blue and grey stripe, the wrong side is a tiny grey dot on a blue background.

Step 1:  Cut out the pattern.  

The main piece needs to be cut once, on the fold.  The crotch piece needs to be cut 4 times, so cut it out twice through a double thickness of fabric.

Step 2: Sew the crotch piece.

Arrange the crotch pieces so that you have 2 sets, right sides facing in. 

Place one set on top of the other.

Sew through all 4 layers at once, down the CF seam (on the pattern, this will be the un-notched seam).  I have used an overlocker to sew this seam.  If you do not have an overlocker, try a narrow zig-zag stitch.

Open out the top layer of fabric and the very bottom layer of fabric.

You should now have a double layer crotch piece with no exposed seams.

Step 3:  Attach the crotch piece to the main panel.

Sew one side of the crotch panel to one of the curved (and notched, on the downloadable pattern) seams on the main panel, right sides together.  You will be sewing through 3 thicknesses of fabric altogether.

Fold over the main panel and attach the other side of the crotch piece to the other  curved seam of the main panel.

The trunks should now look like this, from the inside.

Step 4:  Sew the inner leg seam.

Flip the trunks over and match up the inner leg seams at the bottom of the crotch seams to the inner leg "slit" on the main panel.  Stitch, being careful to catch the sharp corner at the top of the slit on the main panel.

Step 5:  Hem the trunks.

This can be done with either a cover stitch machine, or a twin needle on a regular machine, or a zig-zag stitch on a regular machine.  I have just used a zig-zag on a regular machine.  The zig-zag stitch allows the leg opening to stretch.

Step 6:  Attach the waistband elastic.

The elastic is sewn with a flat joining seam to minimise bulk.  Commercially, this would be done with a cover stitch.  There are a couple of different stitches you could use on a regular machine.  The photo below shows where I have tested out a few different stitches using a scrap of elastic on some scrap fabric. From left to right, I have tried on the the stretch stitches that comes on my machine, a 3-step zig-zag with short stitch length, a 3-step zig-zag with a longer stitch length and a regular zig-zag.  Have a play around and decide what works best for you.

Stretch stitch on my machine

 3-step zig-zag stitch selector.

You can use the recommended elastic lengths, given with the pattern.  You could also custom measure, making sure that the final measurement is at least a smidge smaller than the fabric to which it is being attached.

Overlap the ends of the elastic by 2 cm.

Stitch to secure.

Divide the waist of the trunks into quarters.  The  easiest way to do this is to mark the CF (centre front) with a pin.

Flatten the trunks so that the CF pin is at one side.  Place another pin at the other side.

Flatten the trunks so that these 2 pins are directly on top of each other.  Put pins at the new sides. 

Similarly, mark the elastic in quarters.  I mark the elastic with a marker, rather than pins, as it is less fiddly.

Sit the elastic on the outside of the trunks, matching up marks on the elastic with pins in the trunks and aligning the top edges.  You can either put the elastic seam at the CF or the CB.  You could always sew a tag over the elastic seam if you did not want it to show.

Stitch the bottom edge of the elastic to the trunks, slightly stretching the elastic to fit the fabric, using the stitch that you decided above.

Turn the trunks inside out and cut away any excess fabric above your line of stitching.

Ta-da!  Completed trunks.

Right side out.

Inside out.