From the USPS on July 28th:
With this new stamp, the Postal Service continues its tradition of celebrating Kwanzaa. The annual Pan-African holiday, which takes place over seven days from Dec. 26 to Jan. 1, brings family, community and culture together for many African Americans. The stamp design features the face of a woman in profile with her eyes closed. Her contemplative demeanor signifies the ways in which observers of Kwanzaa reflect on the seven founding principles, the Nguzo Saba, and their role in everyday life. A kinara (candleholder) with the seven lit candles (mishumaa saba) sits in front of her. Cool tones evoke a sense of inner peace, and vibrant design elements give the artwork a celebratory feel. Art director Antonio Alcalá designed the stamp with original artwork by Andrea Pippins.
New information will appear below the line, with the latest at the top. Kwanzaa in 2020 begins December 26th and ends January 1, 2021.
Updated December 5th:
The Scott catalogue number for this issue is 5531.
Updated September 16th:
Here are the first-day postmarks for this issue: 
The Digital Color Postmark measures 2.43″ x 1.49″ 
The pictorial postmark measures 1.93″ x 1.23″
Updated September 10th from the Postal Bulletin:
On October 13, 2020, in Nashville, TN, the United States Postal Service® will issue the Kwanzaa stamp (Forever® priced at the First-Class Mail® rate) in one design, in a pressure-sensitive adhesive pane of 20 stamps (Item 574900). The stamp will go on sale nationwide October 13, 2020, and must not be sold or canceled before the first-day-of-issue.
With this new stamp, the Postal Service™ continues its tradition of celebrating Kwanzaa. The annual Pan-African holiday, which takes place over seven days from December 26 to January 1, brings family, community, and culture together for many African Americans. The stamp design features the face of a woman in profile with her eyes closed. Her contemplative demeanor signifies the ways in which observers of Kwanzaa reflect on the seven founding principles, the Nguzo Saba, and their role in everyday life. A kinara (candleholder) with the seven lit candles (mishumaa saba) sits in front of her. Cool tones evoke a sense of inner peace and vibrant design elements give the artwork a celebratory feel. Art director Antonio Alcalá designed the stamp with original artwork by Andrea Pippins.
No automatic distribution.
How to Order the First-Day-of-Issue Postmark:
Customers have 120 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office™ or at The Postal Store® website at usps.com/shop. They must 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 – Kwanzaa 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 February 13, 2021.
Technical Specificiatons:
Issue: Kwanzaa Stamp
Item Number: 574900
Denomination & Type of Issue: First-Class Mail Forever
Format: Pane of 20 (1 design)
Series: N/A
Issue Date & City: October 13, 2020, Nashville, TN 37202
Art Director: Antonio Alcalá, Alexandria, VA
Designer: Antonio Alcalá, Alexandria, VA
Artist: Andrea Pippins, Bowie, MD
Modeler: Sandra Lane/Michelle Finn
Manufacturing Process: Offset, Microprint
Printer: Banknote Corporation of America
Press Type: Alprinta 74
Stamps per Pane: 20
Print Quantity: 15,000,000 stamps
Paper Type: Phosphor Tagged Paper, Block Tagged
Adhesive Type: Pressure-sensitive
Processed at: Banknote Corporation of America
Colors: Cyan, Magenta, Yellow, Black
Stamp Orientation: Vertical
Image Area (w x h): 0.77 x 1.05 in/19.558 x 26.67 mm
Overall Size (w x h): 0.91 x 1.19 in/23.114 x 30.226 mm
Full Pane Size (w x h): 5.55 x 5.76 in/140.97 x 146.304 mm
Plate Size: 160 stamps per revolution
Plate Number: “B” followed by four (4) single digits
Marginal Markings:
Front: Plate number in four corners
Back: ©2020 USPS • USPS logo • Two barcodes (574900) • Plate position diagram (8) • Promotional text
The Digital Color Postmark measures 2.69″ x 1.46″ (Corrected August 19th)
The pictorial postmark measures 2.70″ x 1.49″. (Corrected August 19th.)
one design, in a pressure-sensitive adhesive pane of 20 stamps (Item 476700). The stamp will go on sale nationwide September 17, 2020, and must not be sold or canceled before the first-day-of-issue. The Mayflower in Plymouth Harbor pane of 20 stamps may not be split and the stamps may not be sold individually.
The woman in the photographs is Stahl herself! 
She had discussions with the U.S. Postal Service on how many women to include and where. These are not meant to be specific historical figures, but representations. Stahl said she wishes she had fought harder for the black woman to be more prominent in the finished design, which is shown on the right and at the top of this page.
WHAT:
The Digital Color Postmark for this issue measures 2.55″ x 1.49″ 
The Pictorial Postmark for this issue measures 1.66″ x 1.48″
The Scott catalogue numbers for this issue are:
WHAT:
The Digital Color Postmark for this issue measures 2.89″ x 1.39″ 
The Pictorial Postmark for this issue measures 2.74″ x 1.46″
5484 (55¢) Fruits and Vegetables – Red and black plums
The Digital Color Postmark measures 2.97″ x 1.49″ 
The pictorial postmark measures 2.69″ x 1.19″
Red and black plums,
The Digital Color Postmark for this issue measures 2.60″ x 1.31″ 
The pictorial postmark measures 2.70″ x 1.20″
What:
How to View:
Scroll down the page until you see “Posts.”
Select “Pages” and click the “Like” button for “US Postal Service.”(Note: You must “Like” USPS to be able to view the virtual event.)
Mobile view: Open Twitter app. If you don’t have a Twitter account, you can download the Twitter app and create your own account, or open twitter.com/USPS from your phone’s web browser. Once the ceremony begins, the virtual event will appear at the top of the USPS Twitter feed. If the ceremony doesn’t appear, keep refreshing the page until the event appears.
The Enjoy the Great Outdoors stamps artwork depicts five different scenes of various outdoor activities — building a sandcastle, hiking, cross-country skiing, canoeing and biking. In these hand-sketched and painted designs, artist Gregory Manchess uses light and shadow to evoke a sense of wonder for these remarkable landscapes. Surrounding the pane of 20 stamps is a painting showing trees and the bank of a body of water. The small figures of a canoe in the water and a man standing ashore holding an oar are visible at the top of the selvage. The title “Enjoy the Great Outdoors” appears right above the pane of stamps in white lettering. Derry Noyes, a USPS art director, designed the stamps.
The Digital Color Postmark measures 1.85″ x 1.47″ 
The pictorial postmark measures 1.61″ x 1.27″
The U.S. Postal Service is canceling the dedication ceremony for the Voices of the Harlem Renaissance Forever stamps, previously announced for May 21, due to social distancing guidance during the coronavirus pandemic.
The Digital Color Postmark for this issue measures 2.53″ x 1.40″.
The pictorial postmark measures 2.48″ x 1.11″ 
The “special” postmark, for cities other than the first-day city, measures 2.75″ x 1.38″
of the Harlem Renaissance stamps (Forever® priced at the First-Class Mail® rate) in four designs, in a pressure-sensitive adhesive pane of 20 stamps (Item 476400). The stamps will go on sale nationwide May 21, 2020, and must not be sold or canceled before the first-day-of-issue. The Voices of the Harlem Renaissance pane of 20 stamps may not be split and the stamps may not be sold individually.
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 
pane of 20 stamps features 10 different photographs of botanic, country estate and municipal gardens taken between 1996 and 2014. The gardens include: Biltmore Estate Gardens (North Carolina); Brooklyn Botanic Garden (New York); Chicago Botanic Garden (Illinois); Coastal Maine Botanical Gardens (Maine); Dumbarton Oaks Garden (District of Columbia); The Huntington Botanical Gardens (California); Alfred B. Maclay Gardens State Park (Florida); Norfolk Botanical Garden (Virginia); Stan Hywet Hall & Gardens (Ohio); and Winterthur Garden (Delaware). Art director Ethel Kessler designed the stamps with existing photographs by Allen Rokach.
On May 13, 2020, in Winterthur, DE, the United States Postal Service® will issue the American Gardens stamps (Forever® priced at the First-Class Mail® rate) in 10 designs, in a pressure-sensitive adhesive pane of 20 stamps (Item 572700). The stamps will go on sale nationwide May 13, 2020, and must not be sold or canceled before the first-day-of-issue. The American Gardens pane of 20 stamps may not be split and the stamps may not be sold individually.
Brooklyn Botanic Garden (New York);
Customers have 120 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office™ or at The Postal Store® website at usps.com/shop. They must affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:
Issue: American Gardens Stamps
Typographer: Ethel Kessler, Bethesda, MD
Adhesive Type: Pressure-sensitive
WASHINGTON, DC — The U.S. Postal Service honors the 50th anniversary of Earth Day by putting its own stamp on raising awareness of our environment and the communities in which we live and serve. The new Earth Day Forever stamp marks five decades of Americans coming together to celebrate the importance of protecting the environment. The stamp will be available for sale nationwide on April 18.
The Digital Color Postmark measures 2.92″ x 1.36″ 
The pictorial postmark measures 2.42″ x 1.19″
