2.3.4b A2 Pattern drafting and toiles Flashcards
Development of prototypes
Designers communicate ideas to clients
through mood or theme boards, sketched ideas,
presentation boards, 3D simulations and final
prototype products.
* The advantages of CAD presentations are that
they can be revised and amended quickly.
* Life size prototype products allow designs to be
visualised more effectively for fit and proportion.
It also allows the fabric to be tested see how it
handles and drapes in reality.
* Modelling of ideas in the iterative process takes
many forms, but should include an initial sketched
idea, a life-sized calico toile and final prototype.
Components parts can also be modelled and
tested.
* Initial models to test concepts can be in any fabric
or material. However, details should be refined
and more precise further into development.
* Modelling allows for testing of materials,
components, dimensions, scale and fit.
* In industry, materials and components go through
rigorous testing, for example strength, durability,
flammability, crease resistance and shrinkage.
* Compliance with appropriate legislation should
be a consideration when new products are in
development.
* Print and embroidery designs go through similar
iterations to products when in development.
* Digital printing allows test prints to be realised,
quickly eliminating the need for expensive test
runs of fabric prints.
* 3D printing of components parts is an effective
way of modelling new ideas before production
Lay-planning and pattern language
All fashion and textile products comprise of
several different shaped parts. A lay plan maps
out the most economical way to cut the pieces
and minimise waste.
* In industry, a lay-plan would be designed using a
specialist computer programme which is then sent
straight to the cutting table.
* On plain fabrics, template pieces can be
tessellated to minimise waste in between the
pieces.
* One-way prints require all pieces to be cut in
one direction only, which can lead to waste. This
also applies to pile fabrics where shading could
occur if the pile goes in opposite directions on a
garment. This is wasteful, but essential for quality
purposes.
* A universal pattern language consisting of a
series of symbols is used so that all sewers can lay
templates out correctly.
* Failure to follow pattern language can lead to an
inferior end product.
* In hand sewing, tailor’s tacks are used to transfer
critical placement points.
* The straight of grain on a fabric runs the length
of the fabric and parallel to the selvedge edge.
Accuracy in applying this rule is critical if the end
product is to drape or hang correctly.
* The strength in a fabric is along the straight of
grain line.
* Some products require the templates to be cut
on the bias which allows more stretch in the final
product. This means laying the templates out
diagonally on the fabric.
* The bias allows garments to hang or drape better.
The fit is also improved. However, bias cutting can
be wasteful.
Commercial manufacturing
- Hot notch marking
Transfer of critical points such as pocket placements
is done with a hot notch marker. It will bore a hole
through several layers of fabric to mark specific
points. The hole is sealed at the same time. - Fabric spreading machines
Automated fabric spreading machines lay out several
layers of fabric on long cutting tables. Some of these
have suction to prevent the fabric from moving
whilst it is being laid out and cut. - Cutting tools and machinery
The agreed lay plan is sent automatically to the
same machine that has the fabric laid out on it. The
individual pieces that make up a product are cut
automatically according to the lay plan. Laser cutters
are increasingly used in this process. - Straight, round and band knives
These are table mounted hand operated cutting
knives used to cut around product pieces as laid out
in the lay plan. The lay plan is mapped out on paper
and placed on the top of the fabric for the operator
to follow. - Automated die cutters
When constant small shapes are needed such as
those found in a bra, metal die cutters are used.
When force is applied, these will cut through several
layers of fabric. - Laser cutters
As well as being used on cutting tables, laser cutters
can cut intricate and complex shapes out of fabric
that cannot be done in any other way. The laser
beam also seals the edges of the fabric so that it
does not fray. Designs can also be engraved onto
fabric. - Additive manufacture or 3D printing
Three dimensional products can be printed – layer
by layer – creating finished prototype products
including wearable garments and useable
accessories
