More Fabric Shrinkage Info

 The following applies to 4 metres of 100% linen fabric purchased online at Club Tissus . This is the fabric in question:

Fabric after washing and ironing

I had purchased 4 metres and received slightly more, that is 437 centimetres instead of 400 (172 inches).

The width was 150 centimetres (59 inches).

After washing in hot water (as per all recommendations) and machine drying (at lowest setting), and ironing at the Linen setting with steam, the piece measured as follows:

WIDTH: 147.5 cm (58 inches), a loss of 2.5 cm (1 inch);

LENGTH: 434 cm (171 inches), a loss of 3 cm (1.25 inch).

As you can see, the shrinkage was minimal, a little over 1% on the width, and way less than 1% on the length.

CONCLUSION: For this particular fabric, pre-washing would not be justified EXCEPT for the fact that the unwashed fabric was as stiff as cardboard. 

And "stiff" is not what linen is supposed to feel like. The typical drape and slightly wrinkled look of linen can only be obtained by removing the stiffening agent that is applied at the mill.

I will continue to experiment with different fabrics, and report my findings here.