Whether you are looking for see-through underwear, or trying to avoid it, the pictures on a website are not the most reliable way to make your decision as lighting can make a big difference.
The best way to tell how transparent a garment of any kind will be is to read the description and see whether the fabric type is specified.
Chiffon is one of the most commonly used sheer fabrics, as are georgette, tulle, double georgette and organza.
Lace can be quite revealing depending on the pattern, and the sheer sex appeal of bare skin behind rare black lace can never be overstated.
Charmeuse and satin are invariably opaque, but describing a garment as 'cotton' or 'silk' tells us nothing about its transparency.
Cotton is almost always viewed as an opaque fabric, but cotton voile and fine cotton lawn are translucent.
A voile nightgown will most definitely show the shape of the body beneath and if unprinted may show more.
Fine cotton lawn is a luxurious fabric which feels gorgeous next to the skin.
Truly translucent a a blouse in fine lawn will need a camisole or lining to be decent, a nightgown in cotton lawn may be just right.
Tulle is a soft, delicate net like fabric often used for wedding veils.
It was very fashionable in the 1920's and thirties and was sometimes used in multiple layers to made negligees and frills on the matching nightgowns.
Silk tulle is the most luxurious, but almost all types of tulle come in a huge variety of colors.
Very very transparent in a single layer, the edges of tulle do not typically fray, and so may be left unfinished.
Chiffon is the fabric most commonly used for see-through lingerie.
Silk chiffon is very soft, delicate and transparent, nylon and acetate chiffons less so, they can be quite harsh on the skin and less transparent than silk chiffon.
Chiffon nightgowns, if a single layer of chiffon, will not normally be the kind you want to answer your front door in, and won't leave much to the imagination.
Chiffon edges are usually finished, and usually using a double seam, one reason why chiffon garments are often more expensive.
There is one type of chiffon which is a little more subtle, pleasantly transparent rather than glaringly see-through, and this is printed or painted chiffon.
Hand-painted silk chiffon is a glorious fabric with all the draping qualities of silk and the wonderful sensation next to your skin, but provides just a list more coverage.
The same can be said for printed chiffons, some of which can be almost opaque.
Georgette is slightly more opaque than chiffon, but also a soft drapy fabric, double georgette is almost opaque, which in some ways makes it the ideal fabric for lingerie.
In the right light a double georgette nightgown will give a glimpse of the body beneath.
Silk double georgette feels fantastic.
If your aim is to tantalise and tease, this is the fabric for you.
Organza is rarely used in nightgowns as it a stiff fabric, though still transparent.
Organza often seems to sparkle, and this can be great for negligees and the like, but don't expect the fabric to be soft and drapey, it will stand slightly away from you body, but used well, can still be stunning.
For most women, sex appeal in the bedroom is best achieved through a subtle approach.
Cotton lawn, double georgette and printed silk chiffons are the ideal fabrics.