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  <xsd:element abstract="true" id="ntic_NotesToFinancialStatements" name="NotesToFinancialStatements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_NotesToFinancialStatementsAbstract" name="NotesToFinancialStatementsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_OneYearAfterDateOfGrantMember" name="OneYearAfterDateOfGrantMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_OtherCountriesMember" name="OtherCountriesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_PNCBankMember" name="PNCBankMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_PatentsAndTrademarksMember" name="PatentsAndTrademarksMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="ntic_PercentageOfIndividualBonusPayoutDeterminedByActualVersusTargetedEBITOIResults" name="PercentageOfIndividualBonusPayoutDeterminedByActualVersusTargetedEBITOIResults" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" xbrli:periodType="duration"/>
  <xsd:element id="ntic_PercentageOfIndividualsPayoutDeterminedUponAchievementOfCertainPreEstablishedIndividualPerformanceObjectives" name="PercentageOfIndividualsPayoutDeterminedUponAchievementOfCertainPreEstablishedIndividualPerformanceObjectives" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" xbrli:periodType="duration"/>
  <xsd:element id="ntic_ReconciliationOfCostOfGoodsSoldFromSegmentsToConsolidatedTableTextBlock" name="ReconciliationOfCostOfGoodsSoldFromSegmentsToConsolidatedTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_The2007PlanMember" name="The2007PlanMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_The2019PlanMember" name="The2019PlanMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="ntic_TotalFeesForServicesProvidedToJointVenturesGeographicLocation" name="TotalFeesForServicesProvidedToJointVenturesGeographicLocation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element id="ntic_TradeReceivablesExcludingJointVenturesNetCurrent" name="TradeReceivablesExcludingJointVenturesNetCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant"/>
  <xsd:element id="ntic_TradeReceivablesJointVenturesCurrent" name="TradeReceivablesJointVenturesCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="ntic_UnaffiliatedCustomersOutsideTheUSAMember" name="UnaffiliatedCustomersOutsideTheUSAMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_ZERUSTMember" name="ZERUSTMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-11-net-income-per-common-share-reconciliation-of-the-earnings-per-share-computations-details" name="statement-statement-note-11-net-income-per-common-share-reconciliation-of-the-earnings-per-share-computations-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-11-net-income-per-common-share-tables" name="statement-statement-note-11-net-income-per-common-share-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-12-stockbased-compensation-blackscholes-optionpricing-model-assumptions-details" name="statement-statement-note-12-stockbased-compensation-blackscholes-optionpricing-model-assumptions-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-12-stockbased-compensation-tables" name="statement-statement-note-12-stockbased-compensation-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-cost-of-goods-sold-by-segment-details" name="statement-statement-note-13-segment-and-geographic-information-cost-of-goods-sold-by-segment-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-fees-for-services-provided-to-joint-ventures-by-geographic-location-as-a-percentage-of-total-fees-details" name="statement-statement-note-13-segment-and-geographic-information-fees-for-services-provided-to-joint-ventures-by-geographic-location-as-a-percentage-of-total-fees-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-net-sales-by-geographic-location-details" name="statement-statement-note-13-segment-and-geographic-information-net-sales-by-geographic-location-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-net-sales-by-segment-details" name="statement-statement-note-13-segment-and-geographic-information-net-sales-by-segment-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-tables" name="statement-statement-note-13-segment-and-geographic-information-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-total-longlived-assets-by-geographic-distribution-details" name="statement-statement-note-13-segment-and-geographic-information-total-longlived-assets-by-geographic-distribution-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-13-segment-and-geographic-information-total-net-sales-by-geographic-distribution-details" name="statement-statement-note-13-segment-and-geographic-information-total-net-sales-by-geographic-distribution-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-15-fair-value-measurements-assets-and-liabilities-measured-at-fair-value-recurring-basis-details" name="statement-statement-note-15-fair-value-measurements-assets-and-liabilities-measured-at-fair-value-recurring-basis-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-15-fair-value-measurements-tables" name="statement-statement-note-15-fair-value-measurements-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-16-supplemental-cash-flow-information-supplemental-disclosures-of-cash-flow-information-details" name="statement-statement-note-16-supplemental-cash-flow-information-supplemental-disclosures-of-cash-flow-information-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-16-supplemental-cash-flow-information-tables" name="statement-statement-note-16-supplemental-cash-flow-information-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-3-business-combination-preliminary-purchase-price-allocation-details" name="statement-statement-note-3-business-combination-preliminary-purchase-price-allocation-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-3-business-combination-tables" name="statement-statement-note-3-business-combination-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-4-inventories-inventories-details" name="statement-statement-note-4-inventories-inventories-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-4-inventories-tables" name="statement-statement-note-4-inventories-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-5-property-and-equipment-net-components-of-property-and-equipment-net-details" name="statement-statement-note-5-property-and-equipment-net-components-of-property-and-equipment-net-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-5-property-and-equipment-net-tables" name="statement-statement-note-5-property-and-equipment-net-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-6-patents-and-trademarks-net-patents-and-trademarks-net-details" name="statement-statement-note-6-patents-and-trademarks-net-patents-and-trademarks-net-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-6-patents-and-trademarks-net-tables" name="statement-statement-note-6-patents-and-trademarks-net-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-7-investments-in-joint-ventures-condensed-balance-sheet-of-excor-and-all-other-joint-ventures-details" name="statement-statement-note-7-investments-in-joint-ventures-condensed-balance-sheet-of-excor-and-all-other-joint-ventures-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-7-investments-in-joint-ventures-condensed-income-statement-of-excor-and-all-other-joint-ventures-details" name="statement-statement-note-7-investments-in-joint-ventures-condensed-income-statement-of-excor-and-all-other-joint-ventures-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-7-investments-in-joint-ventures-tables" name="statement-statement-note-7-investments-in-joint-ventures-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-8-intangible-assets-net-details" name="statement-statement-note-8-intangible-assets-net-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="ntic_statement-statement-note-8-intangible-assets-net-tables" name="statement-statement-note-8-intangible-assets-net-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
</xsd:schema>
