can't decide if I need FBA

[RachelB]

I am sewing McCall 8032 and the bodice is giving me problems.  I chose a size 12 because the high bust measurement is 34 inches as is mine.  The finished bust measurement is 38 inches.  I measure 37 inches at the largest part of my bust.  This would indicate that I don't need a FBA, but there are drag lines above the bust when I tried on the muslin. Actually, the finished bust of my muslin should be 37.5" because I sewed 3/8" seams instead of 5/8" seams.    I can't post pictures yet, but does anyone have any idea what I should do? Thanks. 

[Renegade Sewist]

@RachelB , you need one. The rule of thumb is "If the difference between your high bust measurement and full bust measurement is more than 2 inches, then it will confirm that you need to do an adjustment". You don't have a massive difference but it still will improve the fit for you.

PS: one inch of ease barely gives you enough room to breathe unless we're talking spandex.

[Efemera]

Yes you need one... a real pain but it will fit better.

[RachelB]

@Renegade Sewist Thank you.  Would a I need a 1 inch FBA?

[RachelB]

@Efemera Thank you.

[Kad]

@RachelB 
If you're using a woven fabric, you need the finished measurements to exceed your actual measurements - this is known as EASE and allows you to breathe, move and generally be comfortable in the garment. The actual amount of ease may vary across the garment with perhaps more at bust and hips than at waist, and also with the design of the garment.
What bust measurement is the size 12 that you are cutting actually intended for? If it's 34" then the garment is designed to have 38" - 34" = 4" ease. Therefore you need to do an FBA to achieve 4" ease above your actual measurements.

[RachelB]

@Kad The high bust measurement of the pattern is 34" and the finished bust is 38". I assumed that since I have a 37" full bust measurement that it would work.  However, that is not a lot of ease so I figured that a FBA would give more ease.  I am just wondering how much to do.

[coffeeandcake]

@RachelB  I have to do an FBA and after much trial and error have found what works for me. I don't think it's an exact science and in your shoes I would most likely do a toile with a 1 inch FBA (pattern front is half of the total front so 1 inch on that piece will give you a 2 inch total FBA) and go from there.

[Kad]

@RachelB , where  have you got the high bust measurement of 34" for size12 from?
 According to McCalls  sizing guide the full bust measurement of a size 12 is 34". The pattern envelope states that the finished bust measurement is 38". This means that the pattern is designed to have 4" of ease at the bust. This indicates that to achieve a similar fit on you, you need to have 4" of ease at the bust ie the garment should measure  37" + 4" = 41".

[RachelB]

@RachelB , where  have you got the high bust measurement of 34" for size12 from?
 According to McCalls  sizing guide the full bust measurement of a size 12 is 34". The pattern envelope states that the finished bust measurement is 38". This means that the pattern is designed to have 4" of ease at the bust. This indicates that to achieve a similar fit on you, you need to have 4" of ease at the bust ie the garment should measure  37" + 4" = 41".

Thank you so much.  I am misreading it then.  I thought the 34" was the high bust measurement.  What size do I actually need then in the bodice?  A size 16?   I have about decided that I need a size 14 in the skirt be because I had to let it out 0.5 inches for it to be comfortable in the skirt.

[Kad]

@RachelB , where  have you got the high bust measurement of 34" for size12 from?
 According to McCalls  sizing guide the full bust measurement of a size 12 is 34".

The pattern is drafted for a body with 2" difference between high and full bust measurements, indicating to me that high bust measurement for a size 12 is 32". I would expect a size 14 to be drafted for a high bust measurement of 34".

[RachelB]

@Kad  Thank you so much.  I am misreading it then.  I thought the 34" was the high bust measurement.  What size do I actually need then in the bodice?  A size 16?   I have about decided that I need a size 14 in the skirt be because I had to let it out 0.5 inches for it to be comfortable in the skirt.

[Kad]

@RachelB
 Size 14 is drafted for a full bust measurement of 36", indicating that the high bust measurement is 34". That is where I would start as the finished measurement of this size is 40". You may still need an FBA as your measurements indicate a difference of 3" between full and high bust , rather than the 2" that the pattern is drafted for, this may cause the waist seam to be pulled upwards in wear. But it'll be a smaller FBA.

[coffeeandcake]

If your high bust is 34" and your full bull bust is 37" you need to choose the pattern size with full bust of 34" ( size 12). Then you will need to add a total of 3" so do a 1.5" FBA on the pattern piece. This will make garment fit across the shoulders and armholes much better and give you the required fullness in the bust.

[Renegade Sewist]

You will benefit from doing a test bodice on  this. Full bust adjustments are straightforward IF all your extra flesh is in the front. If you're a bit fleshy some of the extra needs to be done on the back, it won't all be in the "girls" out front. The only way to figure it out for your current body is trial and possibly error. It can also be from a broad back.

I definitely have some of mine in the back towards the side. It's one reason I like unstructured looser fitting clothes. 

Patterns are just a generalized starting point. In theory once you work out the changes you need for a particular pattern company it should be consistent for that company. Then you work it out for another company.  :thumbsup: