Sewing tutorial

Re-sizing PDF Patterns Part 2

Most PDF patterns for non-clothing items make 1 size of the project. This post is part 2 of 2 about re-sizing PDF patterns to create custom-sized projects. I’m using the So-Sew-Easy Cosmetics Bag With Fold Over Brush Roll (Ankes Brushes Bag Free Pattern) as the example for this tutorial. Click here to read part 1. Continue reading for part 2.

I’m using the following abbreviations:

  • Old-CB = old cosmetics bag (black in colour)
  • F-CB = finished So-Sew-Easy Cosmetics Bag With Fold Over Brush Roll (orange, grey and white in colour)
  • O-Pat = original pattern for So-Sew-Easy Cosmetics Bag With Fold Over Brush Roll
  • R-Pat = resized pattern
  • FCS-CB = finished, custom-sized So-Sew-Easy Cosmetics Bag With Fold Over Brush Roll

In part 1, steps 1 to 4, we found the exterior dimensions and seam allowance of a project, determined the final exterior dimensions for a custom-sized project, checked the volume for a custom-sized project and calculated the resizing ratio. Now we continue with stepss 5 to 10.

Step 5) Select your seam allowance

Applying a re-sizing ratio to entire pattern pieces also applies it to the seam allowance. Multiply the original seam allowance by the resizing ratio to determine how the seam allowance changes. You may either sew your project with the original seam allowance or the resized seam allowance.

Reducing Patterns Reduces The Seam Allowance

The original seam allowance for F-CB is 7mm (~1/4 inch) and multiplying it by 0.87 results in a proportional seam allowance of 6.1 mm. There are 25.4 mm in an inch so using the original seam allowance of 7 mm will not cause an appreciable change in the size of the finished project (it will be slightly smaller)..

Enlarging Patterns Enlarges The Seam Allowance

If  enlarging a project with a 7 mm seam allowance by a resizing factor of 1.5, the proportional seam allowance would by 10.5 mm. This is nearly 7/16 of an inch. Sewing the project with a 7/16 inch or 1/2 inch seam allowance would result in a finished project with similar dimensions to the expected size. If you sewed this same hypothetical project with 7 mm (~1/4 inch) seam allowances, you will end up with a slightly larger finished project than expected. Feel free to choose the option you prefer.

If you are are not using the same resizing factor along all three dimensions, I recommend that you select one seam allowance for the entire project and adjust the customized pattern accordingly.

Be sure to note your seam allowance so that you use it consistently when sewing your project.

Step 6) Identify which other pattern pieces need to be resized.

Now that we’ve determined how the exterior pattern paces. will change, we must examine the remaining pattern paces. to determine if the resizing makes sense for them. Changing the exterior dimensions of a project doesn’t necessarily mean that you want to change all of the interior pattern paces. For example, if your project has credit card slots, reducing or enlarging all of the pattern pieces would result in the new project having credit card slots that are either too small or too big. The card slots to be the same size as in the original pattern in order to function as intended.

Patch Pockets

The O-Pat for the F-CB contains pattern pieces for a Brush Roll/Bag Flap, Brush Flap and Brush Holder. I also created a pattern piece for Patch Pockets. The Patch Pocket pattern piece is sized to fit the width and height of the cosmetic bag and to be sub-divided into three sections. It makes sense to resize it by the same resizing factor as the bag exterior. In order to make the sections of the Patch Pocket a similar size to those of the original pattern the number of sections must be reduced from three to two.

Resizing Patch Pocket Original Size (cm) Resizing Ratio (Custom: Original) Customized Size (cm)
Patch pocket width 19 0.87 16.5
Patch pocket height 19 0.87 16.5
Brush Roll/Bag Flap Width

The original Brush Roll/Bag Flap pattern piece is 3 cm narrower than the bottom of the original Exterior pattern piece. This is so the finished Brush Roll/Bag Flap will fit between the seam allowances of the exterior piece. It makes sense to make the custom Brush Roll/Bag Flap 3 cm narrower than the custom exterior: 22 cm – 3cm =19 cm.

Brush Roll/Bag Flap Length

The original Brush Roll/Bag Flap pattern piece is 30 cm long. The instructions tell me that this pattern piece has 7mm seam allowance on all sides so the finished flap will be 28.6 cm longer ( two seam allowance widths = 1.4 cm). Comparing this length to the paper model, we see how this length is used. The Brush Roll/Bag Flap extends from the centre exterior seam to the front edge of the bag (5.5 cm), up the side (14.11 cm), over the the zipper (0.5 cm) and the rest of the length (28.6 cm-5.5 -14.11 -0.5 = 8.49) goes down the front size. The ratio 8.49:14.11 is 0.60 so we can estimate that the flap goes down ~ 60% of the way down the other side.

Line drawing of the original bag indicating the Brush Roll/Bag Flap (blue)
Line drawing of the original bag indicating the Brush Roll/Bag Flap (blue)

Let’s examine the measurements for the FCS-CB to determine how long the R-Pat needs to be. The flap starts at the centre seam and extends to the front edge of the bag (4.8 cm), up the side (12.3 cm), over the the zipper (0.5 cm) and the 0.6 of the way down the front side (7.38 cm). In addition to this combined length of 24.98 cm, the pattern also needs to have 0.7 cm seam allowances at both short ends. The total length of the flap pattern is 26.38 cm.

Line drawing of the customized bag indicating the Brush Roll/Bag Flap (blue)
Line drawing of the customized bag indicating the Brush Roll/Bag Flap (blue)

We can calculate the resizing ratio between the original Brush Roll/Bag Flap pattern piece and apply it to the Brush Flap and Brush Holder pattern paces.

Resizing Brush Roll/Bag Flap Original Size (cm) Customized Size (cm) Resizing Ratio (Custom: Original)
Brush Roll/Bag Flap width 22 19 0.86
Brush Roll/Bag Flap length 30 26.4 0.88

The resizing ratios for both the width (0.86) and length of resized pattern (0.88) are similar to the resizing ratio for the Exterior (0.87). For simplicity you could also use ratio of 0.87 for the Brush Roll/Bag Flap pieces. I used the resizing ratios in the table for accuracy.

Step 7) Create pattern pieces for your custom project.

To create your custom pattern pieces, multiply the dimensions of the O-Pat pieces by your resizing factor(s) to determine the measurements of your R-Pat pieces.

I create a spreadsheet or table with the original product dimensions, sizes of the pattern pieces, seam allowance, resizing ratio and the customized project dimensions, pattern piece sizes and seam allowance. In the case of my customized SSE Cosmetics Bag with Brush Roll, the information would be similar to that of the below table.

Finished Dimensions Original Bag (F-CB) Resizing Ratio (Custom: Original) Customized Bag (FCS-CB)
Exterior Dimensions 23 cm wide x 13 cm tall x 11 cm deep 0.87 20 cm wide x 11.3 cm tall x 9.6 cm deep
Pattern Pieces Original Size (O-Pat) Resizing Ratio (Custom: Original) Customized Size (R-Pat)
Exterior 36.4 cm wide x 21.5 cm tall 0.87 31.7 cm wide x 18.7 cm tall
Patch pocket 19 cm 0.87 16.5 cm
Brush Roll/Bag Flap width 22 cm 0.86 19.0 cm
Brush Roll/Bag Flap length 30 cm 0.88 26.7 cm
Seam Allowance 7 mm 1 7 mm
Use your printer

If you are resizing all three dimensions (length, width and depth) of your project with the same resizing ratio, you may be able resize the pattern pieces by that ratio when you print them out. Change the print size from 100% to (your resizing ratio * 100).  I printed the exterior pattern piece at 87% of it’s original size for this project.

Re-draw by hand

Gridded pattern paper with a 1 inch square grid is helpful if your pattern is in inches. You can also make your own square-gridded paper using whatever grid size is conveneint.

If you aren’t using the same resizing ratio along all three dimensions, you will have to redraw the pattern paces by hand. Making your own rectangular-gridded paper may help.

I re-drew all the other re-sized pattern pieces by hand for this project.

Check seam allowance

If your selected seam allowance is similar to the proportional seam allowance, you can resize your pattern pieces with impunity.

If your selected seam allowance is dissimilar to the proportional seam allowance, or you are using different resizing ratios along the three dimensions:

  • remove the seam allowance from the original pattern pieces (fold it back, cut if off, or trace out a new pattern piece),
  • enlarge the remaining portions of the pattern pieces, then
  • add your selected seam allowance to the customized pattern pieces.

Here are some photos comparing the original and resized pattern pieces for this project.

Customized exterior pattern piece (pink) and original
Customized exterior pattern piece (pink) and original
Customized Brush Roll/Bag Flap pattern piece (pink) and original
Customized Brush Roll/Bag Flap pattern piece (pink) and original
Step 8) Cut out the fabric and other materials for your custom project.

Cut your fabric and materials according to your resized pattern pieces. Notions such as zippers and velcro may also need to be re-sized for your custom project.

Step 9) Sew your custom project as per the original instructions.

Sew your custom project as per the original instructions for your project. Keep track of your selected seam allowance. You will have adjust the positions and/or measurements described in the original pattern by your resizing ratio.

Here are a few photos of the custom sized cosmetic bag that I sewed using my resized pattern.

Interior peice with patch pocket
Custom interior piece with patch pocket
custom exterior peices sewn to zipper
Custom exterior pieces sewn to zipper
Custom Brush Roll/Bag Flap
Custom Brush Roll/Bag Flap
Step 10) Measure your custom project.

Measuring your  re-sized project confirms final dimensions match the planned final dimensions. Record the dimensions in case you want to use you custom pattern again.

My goal was to create a FCS-CB that was 9.6 cm deep, 11.3 cm tall, and 20 cm. When sewn, using my R-Pat, my custom-sized SSE Cosmetic Bag was 9.6 cm deep, 11.3 cm tall, and 20.3 cm long. I know I had a little of trouble boxing the corners and I think the additional 0.3 cm of length along the bottom seam is the result.

Here are some photos of my 3 makeup bags.

Front view of old makeup bags
Front view of old makeup bag (black) and custom-sized makeup bag (blue & white)
3 makeup bags, increasing in size from left to right
Top view of old makeup bag (black), custom-sized makeup bag (blue & white) and original-size makeup bag (orange, grey & white)

I’ve been using my custom-sized makeup bag for several months and it has performed admirably for storing and using my travel-sized makeup and makeup brushes.

Here are some photos of my custom-sized makeup bag in use.

Makeup bag closeup
Oblique view of custom-sized makeup bag in use

 

Top view of open makeup bag
Top view of open custom-sized makeup bag in use

I love it so much that it has become my everyday makeup bag.

Have you re-sized PDF patterns? If so, what method did you use? Comment below and/or Pin Me For Later.

Tanya

Sewn By Tanya Sewing Tutorial: Re-sizing PDF Patterns Part 2
Sewn By Tanya Sewing Tutorial: Re-sizing PDF Patterns Part 2

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