Page 249 - Anthropometry, Apparel Sizing and Design

Evaluation of pattern block for fit testing 241

Longitudinal side balance б ls shows the position of points 43 and 45 on the structural
waist level /41-471/; б ls is equal to half of the difference between the similar dimen-
sions belonging to the body and the clothes:

0 00
ð
б ls ¼ 0:5 =14 -332-43= + =14 -352-45=ð½ Þ AL +2 BL BL APB ފ: (9.17)
ð
00
where /14 -332-43/ is the length of back armhole, cm; /14 -352-45/ is the length of
0
front armhole, cm; AL is the armpit length measured between APB and APF across
SP, cm; BL is the back length, cm; BL APB is the part of BL measured from BNP to
the horizontal level across APB, cm.
The equation for calculation of б ls is:

б ls ¼ 0:5 T tm3 + T tm:sp + E bending 2М WL +1:6T pad + E AHS : (9.18)
where T tm3 is the ease allowance that equals to the thickness of the textile material
located along the side balance line /11-41/, cm; T tm.sp is the ease allowance that equals
to the thickness of the shoulder seams, cm;E bending is the ease allowance appearing as
an additional value due to the bending of clothes around the shoulder area, cm; М WL is
the distance between the natural waistline WL and the narrowest structural level of
clothes /41-471/, cm; T pad is the thickness of the shoulder pad, cm; E AHS is the ease
allowance to the armhole shaping, which is equal to the shrinkage along the back arm-
hole, cm (see Fig. 9.7, n 2 ).
2nd balance concordance between б ls and б lfb is

Δ 2 ¼ б ls -б lfb ¼ 0:8T pad +0:5 E AHS : (9.19)

If a shoulder pad is absent and E AHS ¼0, Eq. (9.19) becomes simpler:

б ls ¼ б lfb : (9.20)

For a balanced pattern block of one-layer clothes such as a man’s shirt, woman’s dress,
and blouses (without shoulder pad), the proportion between the three indicators is

б li ¼ б ls ¼ б lfb : (9.21)

Fig. 9.9 shows the misfit problems arising from wrong calculations of longitudinal
balance.
Because textile materials of a shirt are usually very thin, T tm.b1 ¼T tm.f2 ¼ T tm.b2 ¼
T tm3 . E bending ¼0. T tm.sp ¼0. Fig. 9.9 presents three possible situations with different
proportions between the indicators of longitudinal balance:
(a) б li ¼ б lfb ¼ б ls ; Δ 1 ¼Δ 2 ¼0. As Fig. 9.9A and D shows, the surface of the shirt is smooth, the
bottom is in a well-designed position, and the side seam is vertical. So, the pattern block is
balanced and the shirt is well-fitted;