Updated June 5th: The Scott catalogue number for this issue is 5199.

Updated April 17th: Here is the Digital Color Postmark for this issue:

It measures 2.97″  x 1.23″. There is also a pictorial first-day postmark: It measures 2.93″ x 1.38″.

Updated April 7th:
[USPS media advisory]
New Celebration Corsage and Boutonniere Forever Stamps
Perfect for Birthday, Prom, Anniversary and other Celebration Invitations

What:
First-Day-of-Issue dedication ceremony for the Celebration Corsage and Boutonniere Forever stamps. The event is free and open to the public.

When:
Tuesday, May 2, 2017, 11 a.m.
Where:

Missouri Botanical Garden
Shoenberg Theatre
4344 Shaw Boulevard
St. Louis, MO 63110

The public may RSVP online at usps.com/celebrations. Followers of the U.S. Postal Service’s Facebook page will post a video of the event at facebook.com/USPS. Share the news on Twitter and Instagram using the hashtag #CelebrationStamps.

Background:
The Postal Service is issuing two Forever stamps that are perfect for mailing anniversary, birthday, prom and other life celebrating invitations enclosed with RSVP cards.

The new Celebration Corsage two-ounce Forever stamp can accommodate the weight of heavy invitations for birthdays, weddings, anniversaries, and other celebrations, oversized greeting cards for all occasions, and mailings such as small gifts that require extra postage. The stamp image is a photograph of an arrangement of ranunculus with accents of hypericum berry, Astrantia and seed eucalyptus.

Similar in design to the new two-ounce Celebration Corsage stamp, the Celebration Boutonniere First-Class Forever stamp can be used for wedding RSVP cards. It is also perfect for party invitations, thank-you notes, announcements, birthday cards, Father’s Day cards and other occasions when a beautiful stamp is fitting. The stamp art features a photograph of an arrangement of ranunculus, with floral accents of succulents, Astrantia, Berzelia and clubmoss greenery.

Both stamps were arranged by floral designer Carol Caggiano and photographed by Renée Comet. Art director Ethel Kessler designed the stamp. Sold separately in panes of 20, the stamps will be issued May 2 and are available for pre-order now.

Updated March 31st:
On May 2, 2017, in St. Louis, MO, the U.S. Postal Service will issue the Celebration Boutonniere First-Class Mail stamp (Forever priced at 49 cents), in one design, in a pressure-sensitive adhesive (PSA) pane of 20 stamps (Item 563300). The stamp will go on sale nationwide May 2, 2017.

Similar in design to the 2-ounce Celebration Corsage stamp, the Celebration Boutonniere can be used for wedding RSVP cards. It is also perfect for party invitations, thank-you notes, announcements, birthday cards, Fatheræs Day cards, and other occasions when a beautiful stamp is fitting. The stamp art features a photograph of an arrangement of Ranunculus with floral accents of succulents, Astrantia, Berzelia, and clubmoss greenery. The ribbon wrapping the stems harmonizes with the colors and textures of the plant material. The boutonniere was arranged by floral designer Carol Caggiano and photographed by René Comet. Art director Ethel Kessler designed this stamp.

Stamp Fulfillment Services will not make an automatic push distribution to Post Offices.

How to Order the First-Day-of-Issue Postmark:
Customers have 60 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office, at The Postal Store website at usps.com/shop, or by calling 800-782-6724. They should affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:

FDOI — Celebration Boutonniere Stamp
USPS Stamp Fulfillment Services
8300 NE Underground Drive, Suite 300
Kansas City, MO 64144-9900

After applying the first-day-of-issue postmark, the Postal Service will return the envelopes through the mail. There is no charge for the postmark up to a quantity of 50. There is a 5-cent charge for each additional postmark over 50. All orders must be postmarked by July 2, 2017.

Philatelic products for this stamp issue are as follows:

• 563310 Digital Color Postmark Keepsake, $11.95
• 563316 First-Day Cover, $0.93
• 563321 Digital Color Postmark, $1.64
• 563324 Framed Art, $19.95
• 563330 Ceremony Program, $6.95

Technical Specifications:

Issue: Celebration Boutonniere Stamp
Item Number: 563300
Denomination & Type of Issue: First-Class Mail Forever
Format: Pane of 20 (1 design)
Series: N/A
Issue Date & City: May 2, 2017, St. Louis, MO 63155
Designer: Ethel Kessler, Bethesda, MD
Art Director: Ethel Kessler, Bethesda, MD
Typographer: Ethel Kessler, Bethesda, MD
Photographer: René Comet, Washington, DC
Modeler: Sandra Lane/Michelle Finn
Manufacturing Process: Offset, Microprint
Printer: Banknote Corporation of America
Printed at: Browns Summit, NC
Press Type: Alprinta 74
Stamps per Pane: 20
Print Quantity: 500,000,000 stamps
Paper Type: Phosphor Tagged, Overall
Adhesive Type: Pressure-sensitive
Processed at: Banknote Corporation of America, Browns Summit NC
Colors: PMS Cool Gray 9/Gray, Cyan, Magenta, Yellow, Black
Stamp Orientation: Vertical
Image Area (w x h): 0.77 x 1.05 in./19.56 x 26.67 mm
Overall Size (w x h): 0.91 x 1.19 in./23.11 x 30.23 mm
Full Pane Size (w x h): 5.425 x 5.635 in./137.80 x 143.13 mm
Plate Size: 400 stamps per revolution
Plate Numbers: “B” followed by five (5) single digits
Marginal Markings:
Front: Plate numbers in four corners of pane
Back: © 2016 USPS • USPS logo • Plate position diagram • Barcode (563300) in upper right and lower left corners of pane • Promotional text

From the USPS, November 22nd, 2016:

This new Forever stamp is similar in design to the two-ounce Celebration Corsage stamp and can be used for weddings and RSVP cards. It also is perfect for party invitations, thank-you notes, announcements, birthday cards, Father’s Day cards and other occasions. The stamp art features a photograph of an arrangement of ranunculus, with floral accents of succulents, Astrantia, Berzelia, and clubmoss greenery. The ribbon wrapping the stems harmonizes with the colors and textures of the plant material. The boutonniere was arranged by floral designer Carol Caggiano and photographed by Renée Comet. Art director Ethel Kessler designed the stamp.