A feature of linen fabrics is their relatively high roughness that can be inappropriate for garments or bed clothes. In principle linen becomes softer with time. Already after short usage linen things becomes visibly softer. 

Fortunately, when it is needed, technologies of artificial softening can be applied. By artificial softening the fabric is being washed with addition of special enzymes. As the result the fabric becomes not just softer but acquires a peculiar texture. Non-ironed enzyme washed fabric looks crumpled, at some extent such crumpled texture preserves itself after ironing as well. 

However when ordering it should be taken into account that such treatment leads to considerable shrinkage of the material - up to 10%. On the other hand, the finished product sewn from preliminarily softened linen will not shrink anymore. 

It should be mentioned that such treatment is not recommended for blend fabrics with linen content less than 40%

In the picture an non-ironed F101-10 enzyme washed fabric (top) and the same non-treated fabric (bottom). Enzyme washed fabrics are denoted "soft".

Besides that some fabrics are softened already by the manufacturer. Such fabrics are identical externally to normal ones, possess the same density and texture, but feel much softer. Material treated in a such way is the best choice for sewing garments and top quality bed clothes. Fabrics with the factory softening are denoted "s", softening plus additional shrikage that can be provided as an extra treatment is denoted as "s sh".