I sent an LOR and an SASE in a 9" x 12" envelope to Chelsea Kane on 7/09/2012.
The address I sent to was:
Chelsea Kane
901 N. Highland Avenue
Los Angeles, CA 90038
I received her response back on 8/11/2012. She sent back two pictures (one for me and one for my sister). We loved her on Jonas and now on Baby Daddy! They are authentic autographs. For proof, I included a picture of mine and my sister's autograph below as well as the return envelope. She did use our SASE.
Here are the picture:
My Chelsea Kane autographed picture
My sister's Chelsea Kane autographed picture
The return envelope
I hope this is super helpful! If you have any questions, please feel free to ask!
Authentic TTM: Emma Watson, Daniel Radcliffe, Rupert Grint, Lindsay Lohan, Robin Williams, Kat Von D, Ashley Benson, Erin Sanders, Alex Flinn, Cassie Scerbo, Nastia Liukin, DC Cupcakes, Mark Salling, Ayla Kell, Jennifer Lawrence, Matthew Lewis, Gabrielle Douglas, Katharine McPhee, Jay Leno, Jordyn Wieber, Candice Accola, Steve Martin, Josie Loren, Michael Welch, Zach Roerig, Alan Rickman, Chelsea Kane, Josh Hutcherson, Maggie Smith, Megan Hilty, Debby Ryan, Cameron Diaz, Sam Claflin, Jennette McCurdy, Nicole Anderson, Julian Morris, Heather Morris, Katie Leclerc, Max Schneider, Amanda Seyfried, Ian Harding, Keegan Allen, Kat Graham, Margaret Cho, Cher Lloyd, Tim Allen, Bradley Cooper, Rachel McAdams, Nikki Reed, Matthew McConaughey, Sutton Foster, Josh Dallas, Miley Cyrus, Channing Tatum, Jenna Dewan-Tatum, Elle Fanning, and Dakota Fanning.
IP: Chuck Norris, Jen Arnold, Allstar Weekend, Kendall Schmidt, Carlos Pena, Logan Henderson, James Maslow, and more
Congrats!! I think I am going to write to her soon, I really liked her on Jonas.
Favorite autographs: One Direction <3, Paul Rudd (VV), Jake M Johnson (via private address), Katie Leclerc x2 (in person & ttm) Most recent: Katie Leclerc - obtained in person! Recently sent: Austin Butler, Bam Margera, Vanessa Marano, Lucas Grabeel, Kellan Lutz, Edie Falco, Scarlett Johannson (VV), Zach Galifianakis, Taylor Swift, Channing Tatum, Willie Roberston (for my husband) and Max Greenfield
Thank you all for your sweet comments I definitely hope you have as great of a success with her as I did!
Authentic TTM: Emma Watson, Daniel Radcliffe, Rupert Grint, Lindsay Lohan, Robin Williams, Kat Von D, Ashley Benson, Erin Sanders, Alex Flinn, Cassie Scerbo, Nastia Liukin, DC Cupcakes, Mark Salling, Ayla Kell, Jennifer Lawrence, Matthew Lewis, Gabrielle Douglas, Katharine McPhee, Jay Leno, Jordyn Wieber, Candice Accola, Steve Martin, Josie Loren, Michael Welch, Zach Roerig, Alan Rickman, Chelsea Kane, Josh Hutcherson, Maggie Smith, Megan Hilty, Debby Ryan, Cameron Diaz, Sam Claflin, Jennette McCurdy, Nicole Anderson, Julian Morris, Heather Morris, Katie Leclerc, Max Schneider, Amanda Seyfried, Ian Harding, Keegan Allen, Kat Graham, Margaret Cho, Cher Lloyd, Tim Allen, Bradley Cooper, Rachel McAdams, Nikki Reed, Matthew McConaughey, Sutton Foster, Josh Dallas, Miley Cyrus, Channing Tatum, Jenna Dewan-Tatum, Elle Fanning, and Dakota Fanning.
IP: Chuck Norris, Jen Arnold, Allstar Weekend, Kendall Schmidt, Carlos Pena, Logan Henderson, James Maslow, and more
Upload your pictures here: 
I definitely hope you have as great of a success with her as I did!
Great Success 
