
Two W .B. Corsets: Left, 1907; right 1910. Both are “Reduso” corsets for stout women, pictured just three years apart.
I have quite a collection of corset ads from the backs of Delineator and Ladies’ Home Journal — but it’s just a sampling. Nevertheless, there seems to be a continuing message from advertisers to women, and that message is, “There is something wrong with your body.” In addition to being re-shaped, it needs to be “improved” and “confined.”
This is a selection of corset and padding advertisements from just one source, Delineator magazine.
1907: S-Bend and Padding

Ad for Set Snug Underwear, Delineator, October 1907.
Although that ad didn’t sell padding, it shows the nearly-impossible ideal figure of 1907.

This W.B. Nuform corset was designed to give the “chicness and charm of figure” of the Gibson Girl. September, 1907.
A chic figure might well require some padding, as well as distortion and an unnatural posture:

H & H Pneumatic Bust Forms were inflatable [and recommended as a flotation device.] In a range of shapes, including “Round… Oblong, convex and concave….” July 1907.

“Are You Thin?” December 1907. Parisian Perfect Form padding for the “back” and hips. You can see it under the corset, especially in the back view.)
“When Nature Slips a Link, Art Steps In. Don’t be Ungracefully Slender a Day Longer….”

The Hip Form Health [!] Skirt will create a bulging bottom [below an unnaturally tiny waist.] November 1907. The text describes it an a petticoat.

American Lady Corset ad, September 1907. Delineator.

“Any woman can find a G.D. Justrite that will bring out the lines of her figure.” G.D. Corset ad, October 1907. Delineator.
… it was always possible to have too much of a good thing:

A Nemo Self-Reducing Corset ad. November 1907.
This ad for a Sahlin Perfect Form corset for slender women seemed to offer a less restrictive garment than those which depended on tight-lacing…

Ad for the Sahlin Perfect Form and Corset Combined, October 1907.
… but on closer inspection, what it really offers the slender woman is a curved, boned bodice which produces the effect of a larger, “stylish high bust” without padding.

It’s a bust improver that improves posture as well as creating a bulging bosom by the use of curved boning.
1910 Corsets: Straightening Out Some of Those Curves

In 1910, swaybacks were out, vertical was in. Two dress illustrations from Delineator, June 1910.

Two W. B. Corsets from March 1910. A mercifully straighter spine than 1907 is combined with a full bust and tiny waist.

Another ad for an inflatable bust improver. Ad for the Nature’s Rival Air Form corset waist, March 1910.
In contrast to an artificially tiny waist, a full bust was encouraged.

Ad for National Corsets, February 1910.
The disappearance of the 1907 sway-back style left some manufacturers off balance:

American Beauty corset ad, March 1910. Apparently a transitional style.

Ad for American Lady corsets, April 1910.
If your breasts were in danger of overflowing your corset top, a “confiner” could be stitched to the corset:

Gossard “bust confiner” made to be sewn to the top of the corset, as shown here.

This J.C.C. corset from 1910 starts low on the bust, and extends far down the thighs. Notice the extension which supports the stocking garters.
These corsets are very long.

Two corsets from an ad for J.C.C. Corsets, March 1910.
Above: The corset was moving down, over the thighs, but in 1910 it still offered some bust support.

The front and back views of a Kabo Corset, March 1910. Delineator.

“The most stylish and serviceable corset made.” Kabo corset ad, March 1910.
To emphasize the change in corset shapes from 1907 to 1910:

Left, 1907 Gibson Girl shape and posture; right, a longer, more vertical corset from 1910.
NOTE: I am not writing an authoritative history of corsets, just offering images from one or two sources in the hope that serious researchers will find them helpful. All of these illustrations come from Delineator magazines.
Coming soon: Corsets continue to change from 1910 to 1914.