As I mentioned in Part 1, when the casual, sportswear look became chic in the nineteen twenties, clothes for actively playing tennis and for watching tennis and other sports began to be illustrated together. A two-page layout in the May, 1929 issue of Butterick’s Delineator magazine contains a few surprises when you read the pattern descriptions.
On page 32, the caption is “Delineator Backs the Tennis Frock against all sports styles,” but not every pattern illustrated in the article is for actively playing tennis.
On the opposite page, the caption is “Necklines Have Style News for all on the sidelines,” i.e., for spectators.
Also illustrated on the same two pages — at the tops — were these outfits:

Butterick patterns 2626, 2603, 2555. From “Delineator Backs the Tennis Frock.” Top of page 32, May, 1929.

Delineator, May 1929. Detail from top of page 33. “Necklines Have Style News for all on the sidelines.”
It’s pretty clear that those two dresses, Butterick patterns 2605 and 2589, are a bit fussy for active sports, in spite of their pleated skirts; but what are we to make of the woman in a columnar, sleeveless, wrap dress, holding a tennis racket and wearing tennis shoes and socks?
Is pattern 2555 really a tennis dress? I can see that bottom button popping right off if she lunges for a low ball.
It’s interesting to look at the alternate views of these dresses, too. The style details from the front don’t necessarily carry to the back. It’s obvious that — as with this 1971 pattern — the pattern company is trying to multi-purpose the designs: with sleeves, or sleeveless; for playing or watching; in plaids or solid colors, etc.

Simplicity No. 9417, dated 1971. Tennis dress and shorts, or tunic and long trousers. Click to enlarge
The Article, Pattern by Pattern, page 32. Delineator, May 1929.
Butterick 2555: Double Breasted Wrap Dress
Butterick 2603: Tennis Dress with Polka Dot Trim

Butterick pattern 2603, May 1929. This is a tennis dress. “An amusing version of the sleeveless white tennis frock has a polka dot collar and a knot of polka dots on the pocket.” All the pleats are in the front of the skirt, a common practice in the 1920’s.
Butterick 2616: Demure in front, low in back

Butterick pattern 2616, for jacket and dress. May 1929. The back view is a surprise — except that tennis dresses were often low backed. The deep V-neck in back “may be of different lengths.” The skirt has pleats in front and back. Available in sizes up to 44 inch bust.
More “Sunburn Fashions”
This chiffon resort dress is from Hattie Carnegie; although definitely a spectator dress (with matching jacket and scarf) it has a back like the tennis fashions that follow.

Sun-back dress from Hattie Carnegie, 1929. “The intense flower tints which look so well against a bronzed complexion appear in this Hattie Carnegie chiffon afternoon resort frock with an unconventional neckline and three-color jabot.”
Butterick 2551: The Evening Back

Butterick 2551, May 1929. “This frock, a sunburn fashion, is cut with a sun back — the strap across the shoulders holding it in place.” That would allow you to play tennis in it; the skirt is pleated in front. It looks very different in two colors.
Butterick 2531: The Sun Frock

Butterick 2531, May 1929. “The woman of fashion exposes arms, legs and back to the healthful rays of the sun.” Pleated skirt, front and back.
The front and back of this dress echo each other, but I don’t think I would have guessed at the low back from an illustration of the front!
Butterick 2635: Sleeveless Tennis Frock

Butterick 2635, May 1929. “A sleeveless tennis frock that may be cut with a sun-back.” The pointed trim line in the front is not echoed in back.
In the back view, she is wearing tennis shoes and socks, but will the high front neckline keep the dress on when she bends over to pick up a ball?
Pattern by Pattern, Delineator, page 33
Butterick 2625: White with an accent of color, polka dots

Butterick 2625, May 1929. “White with an accent of color is very smart.” A spectator dress, more elaborate than the polka-dot trimmed tennis dress pictured earlier (No. 2603.)
Butterick 2633: Checked fabric, kimono sleeves, lingerie collar

Butterick 2633, May 1929. “The checked frock is one of the first sport fashions.” The same page featured other dresses with “lingerie collars.”
Butterick 2637: Tucked waistline, pleats at the sides
Butterick 2621: Kimono sleeves and a monogram

Butterick 2621, May 1929. A Patou-like monogram, but not a word about playing tennis, in spite of her practical shoes.
On the same page….
Butterick 2605: Color contrast in a 4-H dress

Butterick 2605, May 1929. “Contrast in color is the season’s most predominant note. . . . This two-piece frock can be used for a 4 H club uniform. Designed for . . . 15 to 20 years.”
Those 4-H club girls must have been fairly accomplished dressmakers. As illustrated, the soft fabric looks like silk, but the 4-H girls would probably have used cotton.
Butterick 2589: Lingerie touches

Butterick 2589, May 1929. The “lingerie touches” (delicate fabric ruffles) are attributed to Patou and to London Trades (a 1920’s designer name.) Available in bust sizes 32″ to 44″
Finally, also from 1929, the tennis dress I showed at the very top of this post, Butterick 2549 :

Butterick 2549, June, 1929. “An evening-back tennis frock with a detachable panel that may be buttoned up to cover the low decolletage if you do not want to tan.”
The same criss-cross back straps are a detail in these dresses for younger girls: