This challenging Mexico Exporta series, globally known and very popular, is being collected according to the criteria of the 14 papers, going well beyond Scott and Michel listings, if you have not done so yet, go ahead and start studying the characteristics of the 14 papers, you can find inside my ebay store, a complete "classification listing" and a "classification guide" of all the stamps of this series, ordered by papers, look for them in the "other" sub-category under the corresponding series category.
The paper classification is made according to: watermark, normal or granite, luminescence on both sides, thickness and satin finish. The stamp classification add: denomination, color, perforation, burelage, and plate size.
The paper 6 characteristics: medium thickness ( 85g/m2 ), without watermark, glossy, fluorescent whit blue anverse, fluorescent whit blue reverse. Period of emission: 1982 thru 1984
All Mexico Exporta etiangui 326 stamps could be found here at etiangui Ebay store ( stores.ebay.com/etiangui/ )