From sloper to sleeveless top

After I created the slopers (see previous project) the next step was to try and make something out of it. I decided to make a pattern for a simple A-line sleeveless top. Should not be that difficult, right?
So, here I will describe all the steps I took to create this top. From drafting the pattern, to basting, to making modifications. I will not go into sewing details, as the point of this project is patternmaking, but in terms of sewing this should be a simple project.

I used a sloper made using instructions from the Bunka Fashion Series, Garment Design Textbook 1: Fundamentals of Garment Design. But the same techniques can be used to modify any sloper.
This is the first step in modifying the front of the sloper. In this picture, it is shown in thicker line. I have removed all waist darts – they will not be used for this design. The majority of the work here will be to move the bust dart and add some fullness to create an A-line design.
1. Add length to the bodice: extend the length from the waist to the hem line by amount you wish p- depends on what the you want the total length to be (remember, you can always lengthen/shorten at the end).
2. Draw a line from the bust point “BP” perpendicular to the hem line. Mark point “A”. This line will help us move some of the bust dart to add fullness.
3. Decide the amount of fullness you want to add to the hemline and mark it as A1. In this case I chose 7cm – so distance A to A1 is 7 cm, which means I will add a total of 14 am to the width at the hem line in the front (as compared to the width around the waist). This is a completely arbitrary number, however, it is limited by the size of the dart: if you were to cut from A to BP and rotate the lower left part of the pattern clockwise around BP, to close the bust dart, and then measure A to A1 – that would be the max A to A1 length.
4. I will also add some fullness on the side – 2 on each side. So draw line from B (the original corner) to B1 2 cm long. Connect B1 up to the underarm point – this line will be the new side seam line. Again, choosing 2 cm is arbitrary, however, for an a-line design you want to add fullness all around not only on the sides.
Now we are ready for some cutting and rotating…

Note – thick black line – original sloper front, red lines – outline for the new pattern, the sleeveless top.
1. Moving the bust dart to add fullness: cut along the A-BP line and rotate the bottom left part of the pattern clockwise around BP until line A-BP aligns with the line A1-BP drawn in the previous step. Depending on the length of A-A1 you chose in the previous step, you will have some of the bust dart still left . You can close it al the way, which would add a lot more flare to the design, and you would not need to make the underarm dart.
2. Draw the shoulder seam. I wanted the shoulder seam 5 cm long, 4.5 cm away from the neck. Find D1 4.5 cm away from D on the original shoulder seam, and then draw a new shoulder seam by measuring 5 cm from D1 (line D1-E1).
3. Draw the neckline – I chose the depth to be 10 cm from the original (line F-F1). To help me draw the neckline – I drew a horizontal line from F1 and a vertical line from D (intersection at 0) and also one from D1 to 0. D1-0 and F1-0 are guidelines for the neckline.
4. Deep necklines might night lie flat across your chest and need to be tightened. To do that fine a point G on the neckline (about 1/3 lenght from F1, or what I did – drew a line from BP through 0 to neckline). Then find G1 – which should be about 0.3 – 0.5 cm from G, also on the neckline. The deeper the neckline, the more you need to tighten…
5. Mark the position of the underarm dart: measure 3cm from point C to C1 and then connect C1 to BP.

1. Tighten the neckline – cut along G-BP line and then rotate the top left part of the pattern clockwise around BP, until line BP-G aligns with BP-G1 line. Note that the neckline is not smooth – we will fix than in the final step.
2. Move the bust dart to the underarm position – cut along the C1-BP line and rotate clockwise around BP until the original bust dart is completely closed.
3. Finished dart should be a little shorter that the original sloper dart – this is to make the final design less “pointy” and thus smoother around the bust. Draw a line through the middle of the dart, through BP and then measure 2 cm along this line from BP to BP1. BP1 is the tip of the final dart in your pattern.
4. Finish all the lines – arm opening, dart lines, side seam and front fold lines, and then smooth the hemline…
And this is your front pattern! Remember – this does NOT include seam allowances. You can add them here if you wish, but I prefer my patterns without seam allowances so I leave it like this…

Now we are ready to move to the back…
Again, I used the back of the Bunka sloper, and I removed all the waist darts as we don’t need them for this design.
1. Lengthen – add the same length from the waist to the hem line as you did in the front.
2. To add fullness, we will move the shoulder dart – draw a line from the tip of the shoulder dart to the hemline (point A) and measure 7 cm to find point A1 (sam amount as in the front). Also add 2 cm to the side (draw a line 2 cm from B to B1) and draw a new side seam from B1.

1. Move the shoulder dart – cut along A-O line (A to tip of shoulder dart) and rotate the right part of the pattern counterclockwise around O until line A-O aligns with A1-O. This will close the shoulder dart partially, again how much depends on the length of A-A1.
2. The shoulder dart is small enough that it can be blended into the design – just a little bit of ease at the shoulder seam (in this case the back shoulder seam is only 1 cm longer than the front shoulder seam). Draw a line from C to D to make the shoulder seam straight and then measure 4.5 cm (to match the front) from C to C1. C1 to D1 will NOT be 5 cm as the front because we need to blend the dart. So to find D1 measure D to D1 to match the same distance in the front (this corresponds to line E to E1 in the front). In this case D to D1 is 3.2 cm long.
3. And that’s basically it – just draw a new arm opening, new neckline and smooth the hemline.
This is your back pattern, again, without seam allowances.

Here we will just check if the curves of the arm opening and necklines are smooth between front and back patterns.
Align your patterns along the shoulder seam. The back is a little wider, but that is not a problem.
1. Match the arm openings (as in this picture) and check that the curve of the is smooth. If not, redraw.
2. Move your pattern a bit to match the necklines and check the curve. Redraw, if necessary, to smooth across shoulder seam and fix that little nick created by tightening the front neckline (points G and G1).
That’s it. You are ready to cut…

So as I said, I created a pattern without seam allowances – I like it that way for at least one reason. In a pattern like this – you can change some things. For example, you might want to finish your neckline with a decorative bias tape (as I did) in which case you don’t need any seam allowances around the neckline. But if you wanted to use facing you would need seam allowances. So if I have a pattern without seam allowances I can make this adjustments easily. But, that’s just me.

I used a thrifted cotton sheet to make this… After basting and draping it on the form I saw I had a problem: it was too wide around the bust line, primarily under arms. As you can see in the first picture, it is supposed to lie flat just under arm and then flare out. But it does not. It kind of bulges out… Not a good drape. However, the neckline lies nice and flat.

So why is it so wide? We did not add any ease at the bust line? Why is it so different than the sloper?
That got me thinking… And I think I figured it out…
If you look at the original Bunka sloper, you can see that the bust line crosses almost all waist darts – the exception being the front dart that starts at the BP. By ignoring the waist darts we have added some fullness – in the front it comes to 0.7 cm (not much) but in the back it comes to almost 3 cm. Also, by moving the shoulder dart in the back (since it starts above the bust line) we added an extra 2.6 cm around the bust! So… we need to take some back!

So, with some trial and error, and basting a few time, I took 1cm in the front (at the underarm) and 1.5 cm in the back on both sides (so 2 cm from front and 3 cm from the back altogether). I did not take away from the hemline, just from the top of the side seam, and then redrew the line down hemline.


… this is what the top looks like.
I am very happy with the end result. For all of you trying this for the first time, it might seem terribly complicated, but I think, once you get a hold of moving darts, adding fullness, and other little tricks, you could do this easily. By the time you trace a pattern, figure out what’s wrong with it and what modifications you need to make, than figure out how to make those modifications… you could have drafted your own pattern, from your sloper, that you know will fit you.

I like this process so much (yes I am a geek, I have admitted it before) that I am going to make more of these projects. And I plan to share with you! Unfortunately, it will have to wait a few months… it’s vacation time and I cannot commit to a big project like this. But when school starts I will be starting too. I hope to learn how to draw patterns and I hope you will join me.

Would you like this pattern? You can get it here.

Size: Burda 38 (see size chart).

This file contains a pattern for the A-line sleeveless top in this project (front and back). It has 15 pages in total and does not include any instructions. In addition to parts included in the file, you will need bias tape to finish neckline and arm openings. Seam allowances are NOT included! Before printing the whole file, print only page 1 and measure the square – it should be 5 x 5 cm. Make sure you are printing at 100% scale, and that “borderless” is not checked. If you are using a Mac, use Adobe, Preview did not work for me (consistently scaled the printout, I could never get 100% scaling).

Ask away!

5 thoughts on “From sloper to sleeveless top

  1. Hi Nicole,

    I stumbled into your blog while trying to get free patterns from the Burda website.:)) Your blog is now bookmarked in my favorites.

    I am actually a novice at sewing and definitely pattern making. I created my basic bodice from Fabianna Dardarti’s youtube instructions. I actually had some luck with it in creating simple shirts and blouses compared to the Burda’s instructions for the sloper.

    Anyhow, I’ll be visiting very often and asking lots and lots of questions.

    Re: neckline staying flat (my biggest problem-not with stretch fabrics but with woven fabrics)

    1. With the method you’ve illustrated, you do not have to cut v’s or snip the seam allowance to keep the neckline flat when you sew?

    2. Is there a formula for the distance between G & G1? Where should you mark G on the neckline? Always in the middle or where the curve is deepest?? (OK, please don’t tell to go and buy the bunka book.:))

  2. Hi Nicole,

    I stumbled into your blog and I’ll be visiting often with lots of questions.

    Re: Neckline staying flat.

    1. With this method, do you still have to cut little v’s along the seamline before you sew??

    2. Is there a formula for calculating the distance to use between G & G1? And the position to place G is arbitrary or should it placed where the curve is deepest>

  3. HI, thanks for visiting and sorry for the late reply… holidays and all.

    Re: flat neckline… what I always to first is stay stitch. It helps a lot! And you have to do it right after cutting, I don’t even iron after cutting just to make sure the fabric does not stretch. You can read more about it here:

    If I do the “decorative” bias tape as shown (vs the one you fold back so it’s invisible), I don;t have to snip the seam allowance. If I use bias tape to fold the seam allowance back, then I do snip around the curves. There is a nice tutorial on that too: One note: if you do the decorative (visible) finish – you don;t need the seam allowance. If you leave it, you will end with a smaller opening. For the folded-back finish, you do need the allowance.

    About point G… It’s at about 1/3 up the neckline from the midline. The book says to take about 0.3 to 0.5 cm at the neckline. I just measure 0.5 cm on the neckline down from G (to get G1). Hope this helps.

    Let me know if you have more question.

    Also, I started a new blog where I do more of this. With more instructions and hopefully more detailed ones. You can find it here:

  4. Hi Nina,

    I do apologize for calling you Nicole. I will be checking your new blog often. Thanks for the input.

  5. Thanks for the inspiration. From my sloper i made a simple top with a bias finish just like yours. i enjoy the cleanness of your finished products. Simple -but cool. I even made my own bias which i am very impressed with.
    Once again, thank you

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