How To Draft Custom Trouser Block Pattern

How To Draft A Custom Trouser Block.

211. Trouser patterns  are particularly difficult to learn to draft correctly, even for professional pattern cutters  and tailors who may spend years learning  the skills. They are skills well worth perfecting though, either for fashion school graduates who need added skills to improve their value to potential employers , or to the home sewer needing to better understand trouser cutting techniques for their own use.

Drafting and altering trouser patterns can be very frustrating. It is not easy understanding how to fit trousers correctly. Often the alterations you make in one area will unexpectedly affect the fit in another area. Pattern cutters  dread making new trouser shapes, as they may have to make them over and over before getting the fit just right.

If the pattern cutter is not present at the fit meeting it can be difficult for the designer or garment tech to convey the correct adjustment to the pattern cutter, especially if they don’t actually understand what is happening themselves. It often takes four, five, or six fit meetings to perfect a new trouser shape.

The Trouser Workshop.

We offer a six hour one to one or paired workshop in which you will learn how to cut a custom trouser  pattern block to your own requirements. We can use your own personal body measurements, or a reference garment to create your trouser pattern block.

We run trouser pattern cutting classes and workshops in our London studios. You will learn how to cut mens and ladies trouser block patterns.  All our pattern cutting classes are one to one or paired tuition. Prices are listed below.

Your trouser block can be nett without seams, or it can include seams. For the professional it is normally more efficient to have seams included. You will need to mark and notch all seam and hem allowances, darts, knee position and grain lines.

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What Is A Trouser Block ? 

A trouser block is a pattern template that is used to create multiple new trouser styles of a similar size  and shape, with minimal need for alterations and revisions. A block can be drafted for a fashion brand, or custom made for an individual.

Each clothing brand will have their own unique trouser blocks customised to their ideal customers specific size and shape. Each brand will have  various  trouser blocks in a standard size  for each type of style. There may be a slim fit block, relaxed fit, high waist, low waist, flat front, pleated, etc.

While you may be able to use a flat front trouser block to make a pleated trouser pattern with some adjustments, you could not use a jeans pattern to make a tailored trouser pattern, and vice versa. The shapes are wildly different.

Creating A Toile.

In order to check and finalise the block pattern fit it is necessary to create a toile ( mock-up) made from your personal block pattern, using your personal body measurements.  A toile (muslin) is a prototype of your custom pattern shape made in a suitable inexpensive fabric, usually calico.

What Professional Pattern Cutters Do.

Professional pattern cutters rarely start from scratch to make a new pattern. Rather, they will use an existing pattern as a template that is most like the new style for design and fit. Or they will use a basic block. It’s far better to use a tried and trusted pattern than the expensive alternative of  trial and error – Expensive in both time and money.

These days it is not so important for the professional pattern cutter to have a collection of blocks to create patterns from, as there is usually a large library of suitable styles to use as a base pattern.

Drafting A Trouser Pattern.

it is very rare for professional pattern cutters to draft a trouser pattern from a formula or system. I have been cutting patterns for fifty years and  I ALWAYS start from an existing reference pattern or garment, unless for very rare and specific reasons. Even then, I would have to follow instructions from a drafting system. I know from experience what does and does not look right, so I can confidently adjust the system according to my experience. custom draft

For The Home Sewer.

A home sewer or hobbyist would take forever trying to perfect a custom trouser shape, whether from a system draft, or a basic trouser pattern. The best way would be to find an existing trouser that most closely resembles the size and fit you are looking for. If you have a standard pattern you can adjust this, using the measurements of the garment as a guide.

The Trouser Block Pattern.

A standard trouser block would consist of a front leg, back leg, and waistband. Although it can be cut nett, without seams,

It can made either with or  without seams. For most situations it would be best to include seams as long as all seam allowances are marked and notched clearly. It would not normally include pockets, fly pieces, or belt loops etc.

While a block may have pocket and dart positions indicated, it will not normally include pockets pieces, belt loops, fly pieces or internal pieces.

One trouser block will not be able to make all trouser shape. If you intend on making different shapes of trousers you will need multiple blocks.

The trouser waist is normally located well below your natural waist, so the waistband normally measure significantly more than your real waist.

Your Favourite Trouser.

If you want to copy your favourite trouser shape it may be better to start from a block pattern and transfer the garment measurements onto the block. It is not normally necessary to cut up a garment to copy the shape, but with trousers it can be very difficult for the inexperienced.

Create A Custom Trouser Block.

Trouser shapes are extremely difficult to perfect, even for professional pattern cutters. There seems to be an additional dimension to trousers that does not exist for other garment types.

The mistake a lot of people make is thinking that creating a custom trouser block according to bespoke measurements is just a question of applying those personal measurements to the draft.

It is where and how those measures are applied that counts, because not everyone with the same measurements is the same shape.

If you just use your body measurements to make your custom trouser pattern you will struggle to perfect the shape. You need to use reference garments.

The most important line in any trouser block is the centre back seat angle. This angle controls the rest of the trouser shape.

the centre front seam is sometimes made to be vertical, and sometimes slightly angled. If you actually look at the body sideways on you will see that the stomach actually protrudes below the waist, so you would assume that the cf line should follow the same line. But there is also a factor called stride width to consider. as you walk forward your thigh needs room to move forward.

Ideally the main reference point for a trouser pattern would be the belly button, as this is a fixed recognisable point. But most trousers are positioned well below this point, so the next best position is the crotch level, even this is not a definite point on the body.

Taking Body Measurements.

What measurements are required In order to make a custom trouser block ?  you will need to take a number of accurate body measurements in order to make your trouser block, but you will also need to add a suitable amount of ease, depending on the fit you require. It may be worth referring to a reference garment.

Points Of Measure.

Body Measurements.

Waist – Measured at the smallest part of the waist around the navel.  Trousers are normally cut to fit well below the waist line. The level depends on fashion and style.

Hip – Measured at the widest part of the hip. While pattern cutters will assume the hip to be a specific distance from the waist, for some curvy women this may be more along the thigh line  than the hip line.

High Hip – Measured around 4″ above the natural hip line.

Thigh Girth – Measured just below the crotch line.

Outside Leg – Measured from under band to floor.

Inside Leg – Measured from under fork to floor.

Crotch Depth / Rise – The difference between inside leg and outside leg measures.

Waist to Knee

Reference Garment Measurements.

Knee Girth.

Hem Circumference.

Centre Front Seam Length.

Centre Back Seam Length.

Fork  – The fork is at crotch level where

Rise – This is the height from the fork to the top edge at waist, measured  in a straight line.

Under Band

CF Angle – The centre front line may be straight or slightly angled.

CB Seat Angle –  The seat angle is very important in the trouser draft. It can vary depending on shape.

Seam Allowances.

If you have created your trouser block without seam allowances, then you will need to add these for your final pattern. Most commercial pattern makers use 1/2″ (1.2 cms) allowances for side seams, inside leg seams, centre front and centre back.  Tailors may use inlays  to allow for alterations. The centre back usually has an inlay at the waist to allow for alterations. Inlays may also be added to one side of the inside leg and outside leg seams.

Workshop prices.

The cost for our six hour trouser block making workshop is £280 for one to one tuition. There is a significant discount available for shared  tuition, up to a maximum of four people. We can also offer an online alternative for anyone that is interested.

EMAIL    [email protected]