Slim Pants/Trousers Block

I wish I could tell you that turning a 0-ease Pants Block into a Slim Pants Block is as simple as adding ease to the side seams & inseams. It was not. At least not for me. I did eventually get a block that I’m OK with. But it took many many muslins & I’ve lost count of the tweaks.

So no tutorial. Just some mug shots demonstrating the effect of key alterations I tried. You be the judge of what you would be happy with if you try to do the same. Keep in mind that variable natural lighting may have affected how the muslin looked in the mug shots. And of course the same alterations may have different effect on different body shapes. Hopefully you will get to your happy point more quickly than I did.

Since this is a long & tedious road, let’s start with the destination – then you can skip the journey if details send you to zzzz…..

Slim Pants Block (for non-stretch wovens)

the road from 0-ease Pants Block

Apology for not giving step-by-step rationale for why I tried certain tweaks. The road was too windy & the journey too long ago. Plus I’ve threw away the WIP patterns in a fit of tidying up. In general, I was trying to get rid of wrinkles and add enough wearing ease. I’ve listed all the steps I noted down. The one crossed out were tweaks abandoned, mostly because they didn’t seem to make any difference.

the prep before the journey

Comparing old RTWs & pants made so far…

  • Best fit seems to be the high street wide leg pants in drapy wool crepe. Torso & crotch was still quite fitted, but the legs were loose. There was hardly any puddling. Interestingly the back crotch fork area is stretched. Not sure if this was stretched during wears or if it was part of the design.
  • The designer fitted pants in stretch wool doesn’t fit so well. I got the usual draglines in the crotch & thigh area front & back. Even with stretch fabric, the thigh is still larger than my wearable muslins. But the drapy fabric helps make the legs look slimmer. BTW pardon my hot cross bum. Gotta sort out new undies now my behind has gotten more droopy & squishy }:-)
  • Both RTW pants have shorter crotch height, crotch length, shallower back crotch curve (not so scooped) than my wrap. Yet they still feel comfortable enough. Actually they’re closer to my crotch height measurement. For some reason the wrap derived 0-ease pants block ended up about 1″ longer in crotch height than by measurement.
  • My previous Burda 2015-11-107 fits better than the designer pants, but this was achieved through over-tight waist-to-hip + back princess shaping. Even then slight wrinkling in back thigh, not to mention weird pooling at front crotch – thigh inseam.

Research trouser fitting on Cutter & Tailor…

Granted, most discussion are about men’s trousers. But some of the basic fitting principles probably still apply. These influenced my decision to shift the knee match-points in most of my muslins & subsequent makes based on this Block. In my wrap, the front knee level is lower than the back knee level. I don’t actually manage to match the wrap knee levels precisely, I just try to reduce the difference as much as possible with iron work stretching-shrinking the side seam & inseam lines.

Pattern 1

Don’t ask. This was a stillborn. Didn’t even made it into muslining.

Pattern 2


0) 0-ease Pants Block
1) Add ease at side seam (1/2″ total at waist, widened to 1-1/2″ total at hip)
2) Add ease at darts / princess line instead, with bigger darts (same amounts)
3) Lowered crotch 1/4″
4a) Back hip tilt – pivot at side seam at hip level 1/2″
4b) Curvier & lower back crotch (dotted line)
5a) Back hip tilt – pivot at side seam at bum crease level 1/2″
5b) Add crotch inseam ease 1/8″
6a) Back hip tilt – pivot at side seam at bum crease level 1″
6b) Curvier & higher back crotch + Add leg ease at inseam (1/4″ with extra from thigh up)
6c) Right leg no shifting of match point / ironwork
7a) Straighten legs + Add more ease at inseam from knee up + Curvier Back crotch
7b) Right front add 1/2″ more ease above mid thigh with deeper dart





Pattern 3


8a) Add more ease at inseams (1/4″ – 1/ 2″) + Split darts into 2 per quarter + Increase Back dart width (1/4″ & shift side seam above hip to compensate) + Add more Front waist ease (1/8″ at side seam & decrease inner dart width by 1/8″)
8b) Right side raise waist 1/2″ at side seam
9a) Tried fitting book prominent calf adjustment (effectively deeper back crotch curve + lowered CB waist). No improvement.
9b) Legs straightened even more + Right side pivot at crotch at high hip level to increase side seam length
9c) Testing lengths & high-low waistline
9d) Final lengths for Wearable Muslin 1

⇒ Wearable Muslin 1

Gingham Capri with belt loop – Design Changes:

  • Lower F waist (1″ difference between CF & CB)
  • Contoured waistband 1-1/4″
  • Capri length
  • Fly front
  • Slant-front pockets
  • Belt loops

Assessment after days’ wear:

  • bum-thigh become saggy, waist seem to tilt front up & back down
  • knees baggy & twisted in front & excess pool in back just above knee – excess fabric from drooped back + angle of thigh vs calf too great & stacking of my upper over lower legs too wonky for slim but not skin tight fit to drape smoothly




Pattern 4


10a) More Back Hip Tilt pivoting at side seam bum crease additional 5/8″ (1-5/8″ total) + deeper curve (CB back to curved)
10b) Straighter CB above hipline
10c) Right raise waist 1/4″ at side seam
10d) Shift back thigh ease to inseam, increasing crotch length slightly + more ease from knee down, redistributed between F/B so both F/B knee down are straigher

⇒ Wearable Muslin 2

Gingham Capri without belt loop – Design Changes:

  • Lower F waist (1″ difference between CF & CB)
  • Contoured waistband 1-1/4″
  • Capri length
  • Fly front
  • Slant-front pockets

Assessment after days’ wear:

  • back crotch curve scoop seems too low



Pattern 5

11) Shallower back crotch curve + Less ease at thigh inseam

⇒ Wearable Muslin 3

Brown High-waisted Capri – Design Changes:

  • Lower waist equal 1/2”
  • Contoured waistband 2″
  • Capri length
  • Side invisible zip
  • Side-seam pockets

⇒ Wearable Muslin 4

Brown Mid-rise with Hem Zips – Design Changes:

  • Lower waist equal 3”
  • Contoured waistband 1-1/4″
  • Extended length
  • Fly front
  • Slant-front pockets
  • Hem zippers

Assessment after days’ wear:

  • Weird pooling at front crotch
  • Waist still seem to tilt front up & back down.
    In high-waist version, this caused waist to stick out in the back
    In low-waist version, this caused more bagginess in bum-thigh area
    This problem made these 2 rather uncomfortable to wear.
    Possible causes…
  • waist to high hip ease + contoured waistline (low front high back) that enlarged waist further = waistline sits lower than intended
  • waist ease + full tummy + flat lower back = waistline level even out front-back or even tilt towards skinnier parts – higher in front & lower in back, resulting in back crotch not sitting as intended, drooping causing excess length further down




More hypothesis to test…

  • Not adding ease at waist-to-high-hip OR assume ease means pants will hang lower on waist evenly, so shorten evenly above hip
  • Try 0 ease back + front with pleat – ie all ease on front ???
  • Don’t do high-low waist unless waist-to-high-hip is skin tight & relies on fabric give for ease in this area.
  • Wider legs especially back thigh to calf so fabric doesn’t have to bend to conform to leg shape & ending up with fabric puddle instead above the knee & front twist at the knee – wide enough cone to skim over all curves
  • Reduce back crotch scooping, stretch back crotch fork if possible, raise crotch level a little

Pattern 6


12a) Reduce Back Hip Tilt at crease level by 3/8″ (1-1/4″ total)
+ Add Front Hip Tilt at hip level 1/4″
+ Shallower Back crotch curve
+ Reduce Back inseam thigh ease
12b) Front Hip Tilt at hip level 3/8″ more (5/8″ total)
+ Remove Back ease above high hip
12 c) Testing flared legs
12 d) Testing high-low waist & different rise…settled on:
CB 3/4″ higher than CF
mid-rise = 1″ — 1-1/2″ — 1-3/4″ lower than high-rise (waist)
low-rise = 1″ lower than mid-rise
ditch the extra-low-rise (1″ lower than low-rise)
+ Reduce Front ease above hip to 1/2″ at waist when lowering waist




Pattern 7 (final)

I thought I was done after Patter 6. Unfortunately shortly after I grew my donut waist. So a bit more adjustment was called for.

13) Shift crotch inseam 1/4″ to Back tapering to nothing at mid-thigh
+ shave 1/8″ off thigh side seam
+ increase Front flare 1/8″ below knee at inseam & side seam
+ straighten CF crotch adding 1/4″ ease at Front hip
+ straighten CB crotch adding 1/8″ ease at waist & deeper curve

Assessment after days’ wear:

  • Although there’s still slight bagging under the bum, I’m calling it done.
  • At least front crotch now looks normal.
  • It’s not as slim as I would have like, but can’t be helped if I want to be able to sit down.

Finishing up

  • Traced these onto card paper.
  • Broken the Front & Back pieces into components so I can mix & match style – eg different rises, dart options, leg styles below knee. This also make the Block easier to store in a small place. I don’t have the luxury of a rack of hanging full Block/Pattern pieces.
  • No seam allowance so that I can trace the combination I want to create fashion patterns.

Unfortunately I made a mistake when tracing. Instead of the high-low waistline of Wearable Muslin 5, I traced even level waistlines. No wonder the two pants/trousers I made using this Block came out less comfy than WM5. I only discover this as I prepared the illustrations for this post. Oops. Thankfully with the component approach I only need to redo the above hipline components.

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11 comments on “Slim Pants/Trousers Block

  1. Susan says:

    Well done!! Like Beth, I’m delighted to discover someone else with a similar fitting obsession. It is absolutely an unbelievably frustrating experience, but your dedicated note taking will be of enormous help in my pants fitting odyssey. Thank you so much.

    • I’m glad my documentation can be helpful to you. It makes the effort to create this post worthwhile for me as well!

      Good luck with your pants fitting. Let’s hope yours will be a short plane ride rather than a greek odyssey! 🙂

  2. I admire your note taking! (And your results of course!)
    I have many many pant muslins and didn’t label properly… I’m still some way from achieving basic fit and a long way from slimmer trousers.
    I will refer to your excellent post again. Thank you

    • My notes only appear to be organised. In actual fact there were still a lot of headscratching trying to make sense of them! So don’t feel bad about failure to label everything clearly. It certainly would help. But it most definitely is hard keeping track of all the tweaks & mug shots.

      Do give yourself a better fighting chance with more forgiving fabrics though. I find my block fits somewhat differently depending on the fabric.

      Good luck. Hope you will get to a satisfactory fit soon!

  3. Giulia says:

    I had to explain my husband why I giggled when I saw this post, he was not sure he understood.
    But a well fitted trousers muslin is my goal of the year. Only, I’m starting by a selft drafted.
    I guess the dream, for me, would be to have someone I trust enough on the sewing level to draft them on me, that would save quite some work.
    Excellent post, as always!

    • Thank you Giulia! Glad you had a chuckle over this. Hubby will understand when he gets roped in to help with fittings! 😉

      What instruction are you using for your draft? Shame you don’t keep a blog. Would love to see how you do yours.

      Anyway, good luck with your trousers muslin. May you reach your destination more quickly!

  4. Oh my goodness!!! Now this is what I call dedication…just to think of how much experience in fitting that you’ve gained in this process!
    And yet, it is so important to find the right fit, isn’t it. (I push myself too in this department – tell myself “I will conquer this!”) Most of your photo examples look great, but I can relate where it comes to living in the garment, and how the fit begins to change throughout the day of wear.
    I have to ask, what do you mean by “I grew my donut waist”?
    Great work, and thanks for sharing your determination in conquering fit! 🙂

    • Or OCD? LOL. To be honest it’s a blur. So I don’t know how much experience I’ve actually “gained”! Hence the dread about impeding figure change as I grow older – the donut waist / love handle / swimming ring / muffin top being case in point – middle age spread! Oh the hassle shall have to begin again.

  5. Beth Duffus says:

    Ah, there is someone else out there as obsessional as me when it comes to fitting muslins! It’s an unbelievably frustrating process. Well done for hanging in there. Your post has particular relevance as I’m stealing myself for the final muslin in the set – trousers! I am fully expecting it to be as much hassle as the others (bodice = 12 goes, subsequent fitted shirt block = about another 12 goes). Once you see a wrinkle you can’t unsee it.
    I’m particularly interested in your experience as we are very similar shapes although my front thighs are more prominent. I have saved this page for future reference. Your final muslin looks great.

    • Thank you! I hope yours will go more quickly. Fabric does also affect the fit I discovered. So maybe choosing a more forgiving fabric first will get you some satisfaction early on to keep the refinement going.

      My front thighs are a bit prominent as well, though being the sedentary type not so athletic. Interestingly, referring to Fitting & Pattern Alteration now, I see that the front tilt alteration I did actually looks quite similar to the Prominent Front Thigh alteration in the book (ed 2 p452). The only difference is that my extra crotch/inseam ease is added to the back rather than the front. When I tried adding to the front it looked too baggy & untidy. I’m speculating that having more bias back inseam which is stretched to match front inseam keep the thigh looking slimmer.

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