Posh + Slash Mash!

Posh + Slash Mash!

Hello everyone!

I’m Livia from www.liviality.com, a sewing aficionado who is thrilled to be here on the G+G Blog sharing with you my latest pattern mash/hack - If you like the project and would like to see more of my work, feel free to follow me on Facebook and/or Instagram!

One of my favorite things to do when I love a pattern is think of all the different ways I can use it and how to incorporate it in my wardrobe without having a bunch of repeat models that only differ in print or color. With pattern mashing/hacking the possibilities are endless!

Today I’m showing you how I made this dress by mashing the Posh Top and the Slash Tunic (these are affiliated links that will earn me a small commission at no extra cost to you).

If you’re new to pattern mashing, don’t worry. It’s not as complicated as it may seem and if you don’t understand a step or get stuck, feel free to shoot me a message via one of the links posted above.

Now, let’s get started!


- Posh Top Pattern
- Slash Tunic Pattern
- Knit Fabric (I used about 3yds)
- Paper
- Tape
- Ruler
- Plus your regular sewing equipment.

Got the supplies? Good!
Time to get hacking.


Posh Top

- Print and assemble only the top part of the front and back bodices (think crop top length), plus the neckband piece.You’ll need 3 front pieces and 1 back piece.

- Remove the seam allowance that runs along the armscye of the front bodice piece (on all three).

Slash Tunic

- Print and assemble the long option of the front and back pieces.

- Add length to all pieces. This is optional and only necessary if you’d like it to be a maxi, like mine.

I added 15” by just lengthening the pieces at the bottom. For reference, I’m 5’10”.


This is where most of the work is, I’ll try to explain and illustrate as best as I can but as I said before, feel free to give me a shout out if you need any help.

As the Posh top bodice is cut on the fold and the Slash Tunic features princess seams and back shaping, we’ll have to make a few adjustments before actually mashing them.

NOTE: I printed the pattern on a smaller scale in order to make it easier to photograph the steps.


o PTF – Posh Top Front bodice
o PTB – Posh Top Back bodice
o STFC – Slash Tunic Front Center
o STFS – Slash Tunic Front Side
o STB – Slash Tunic Back



1. Get both front pieces of the Slash Tunic and place them as one piece by overlapping the seam allowance (1/2 inch).

2. Place the PTF on top of it making sure to align them by the armscye. You may need to trim a bit of the ‘on fold’ edge of the PTF as that pattern has a bit more ease than the Slash Tunic.

Mark on the PTF where neckline of the Slash Tunic hits it (now you have 1 Posh Top front bodice piece with this mark and 2 without).

3. Get one of the unmarked PTF pieces and place the STFS on top of it aligning them by the armscye. Trace the curved line of the STFS piece onto the PTF.

Cut on the line drawn and discard the half with “FOLD” in it.

4. Now get the MARKED PTF and place the STFC on top of it, using the mark you previously made and the straight edges to align the two.

Like the previous step, draw the curved line and cut the PTF piece. This time you’ll KEEP the half that says “FOLD”.


5. Now you have one PTF and one PTB piece left.
Place the PTF on top of the PTB, align the armscye and measure the difference between the two.

6. Add that difference to the PTF length as pictured. This will be your new Back piece.
Discard the original PTB.

7. Place the STB on top of the new Back pattern piece and align them by the armscye. Trace the center seam edge and cut the difference, shaping the new Back piece.


8. Before combining the patterns, we’ll use the modified Posh Top pieces to cut our lining.


9. Align the modified pieces on top of their respective Slash Tunic ones. Tape and replace.


10. This is optional and a personal choice. I decided to trim the neckband a bit to make it lower and a bit tighter around the neck.  I removed about 3/4 inch both in length and width.

Your pattern pieces are done.

Now comes the fun and easy part…


11. Sew the lining pieces according to the Slash Tunic instructions. You’ll not sew the shoulder seams. I serged the bottom edge of mine. If you don’t have a serger you may want to leave it raw, as knit fabrics don’t fray (hemming the lining may cause a bit of a bulk on the dress as you wear it).
12. Now we’ll move to the dress pieces, and like on the previous step, follow the Slash Tunic instructions, skipping the shoulder seam step. The only difference will be the slash.
I decided to have only one slash and have it start at mini skirt height.
13. We are almost there! The next step is attaching the lining to the dress.
Insert the lining into the dress RST making sure to align all the seams. Pin or clip in place. Sew or serge along the armscye on both sides.


14. Flip it right sides out, press the seams you’ve just made and topstitch (optional).

15. Time for the neckband.
Sew the band shut, forming a ring. Then you’ll mark the band into four equal parts, using the seam as a starting point. Do NOT fold it in half lengthwise yet.

Find and mark the center of the front and back bodice of the dress.

Pin or clip the neckband (one edge only) to the dress. RS of the neckband against the lining of the dress. Align the seam of the band to the back center seam and center front of the band to center of front bodice. I stretched the band very, very slightly while leaving the side pins of the band centered on the gap at the top of the armscye.

Sew using ¼ inch seam allowance.
(You may want to baste it and try the dress to check for fit)

Flip your neck band up and press the seam allowance towards the unsewn edge of it.

Press a ¼ inch memory seam to the raw edge and fold the band towards the dress. Sew the band shut keeping your stitches as close to the edge as possible.

Hem your dress and you’re done!!!

That’s all from me today.

If you make a Posh + Slash mash following this tutorial make sure to share it with us in any (of ALL) G+G social media platforms and I’ll LOVE IT if you’d tag me so I don’t miss it! <3

I’m Livia Jonker-Yamada on FB and @livia.jy on Instagram.



Back to blog


Love it. All your makes inspire me


Absolutely stunning, totally going to try this

Julia jones

Love your dress! It’s gorgeous! ❤️ And the mashup seems pretty straight forward. Thanks for sharing!

Susan J.

Wow. Just wow. Def on my list of things to try.

Josie A

So elegant! Can’t wait to try this one myself. Love it!!!

Andrea McEnulty

Leave a comment