UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.    )

Filed by the Registrant  x                             Filed by a Party other than the Registrant  ¨

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¨ Preliminary Proxy Statement

¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

¨ Definitive Proxy Statement

x Definitive Additional Materials

¨ Soliciting Material under Rule 14a-12

Aspen Aerogels, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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	*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on June 15, 2016
			Meeting Information
	ASPEN AEROGELS, INC.		Meeting Type: Annual Meeting
			For holders as of: April 20, 2016
			Date: June 15, 2016	Time: 9:00 AM EDT
			Location: Offices of Mintz, Levin, Cohn, Ferris,
			Glovsky and Popeo, P.C.                        1 Financial Center                        Boston, MA 02111
		You are receiving this communication because you hold shares in the above named company.
		This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side).
		We encourage you to access and review all of the important information contained in the proxy materials before voting.
			See the reverse side of this notice to obtain proxy materials and voting instructions.

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	— Before You Vote — How to Access the Proxy Materials
	Proxy Materials Available to VIEW or RECEIVE:
	1. Annual Report          2. Notice & Proxy Statement
	How to View Online:
	Have the information that is printed in the box marked by the arrow     (located on the following page) and visit: www.proxyvote.com.
	How to Request and Receive a PAPER or E-MAIL Copy:
	If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request:
	1) BY INTERNET:         www.proxyvote.com
	2) BY TELEPHONE:     1-800-579-1639
	3) BY E-MAIL*:             sendmaterial@proxyvote.com
	*  If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow     (located on the following page) in the subject line.
	Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before June 01, 2016 to facilitate timely delivery.
	— How To Vote — Please Choose One of the Following Voting Methods
	Vote In Person: Many stockholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares.
	Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow     available and follow the instructions.
	Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card.	Internal Use Only

	Voting items
	The Board of Directors recommends you vote FOR the following:
	1.	Election of Directors
		Nominees
	01	Craig A. Huff                02    Mark L. Noetzel                03    William P. Noglows
	The Board of Directors recommends you vote FOR the following proposal:
	2.	The ratification of the appointment of KPMG LLP as Aspen Aerogels, Inc.’s independent registered public accounting firm for the fiscal year ending December 31, 2016.
	NOTE:  Such other business as may properly come before the meeting or any adjournment or postponement thereof.
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Reserved for Broadridge Internal Control Information      

NAME
THE COMPANY NAME INC. - COMMON	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS A	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS B	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS C	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS D	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS E	123,456,789,012.12345
THE COMPANY NAME INC. - CLASS F	123,456,789,012.12345
THE COMPANY NAME INC. - 401 K	123,456,789,012.12345

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