EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Ralph B. Andy Ralph B. Andy Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Lloyd E. Campbell Lloyd E. Campbell Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Pamela F. Lenehan Pamela F. Lenehan Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries the for fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Jackson W. Robinson Jackson W. Robinson Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Richard B. Scherrer Richard B. Scherrer Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Craig A. Wolfanger Craig A. Wolfanger Director EXHIBIT 24 SPARTECH CORPORATION AND SUBSIDIARIES POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature appears below constitutes and appoints Bradley B. Buechler his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, to act for him and in his name, place and stead, in any and all capacities to sign this annual report on Form 10-K of SPARTECH Corporation and Subsidiaries for the fiscal year ending October 30, 2004, and any and all amendments thereto and to file the same with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof. Dated: January 12, 2005 /s/ Walter J. Klein Walter J. Klein Director