Patwary, Md. Amirul Islam creator Nazhad, Mousa M. Chairperson Basta, Jiri Examination committee Lehtinen, Esa Examination Committee AIT Fellowship Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2011 2010 continuing eng 37 leaves : ill. Recently, there has been a trend in decreas ing the basis weight of medium weight coated paper. Because the paper market becomes competitive, it drives compan ies to keep the market share relying on reducing the basis weight. Taking into account this view point , the effect of basis weight reduction on sheet properties is considered to be evaluated. Softwood ( SW ) frayed fiber and filler share are used to maintain strength and opacity of paper . The b asis weight is varied from 70 gsm to 55 gsm . From t he experimental results , i t is found that in order to maintain acceptable strength and opacity , the basis weight can be decreased from 70 gsm to 60 gsm . Further, f iller retention above 25% decreases the paper strength gradually al though the opacity of paper increase s . A 10% softwood frayed fiber cannot maintain strength if the filler retention is 30%. Ho wever, employing a combination of SW frayed fiber of 10% and filler share of 25% , the strength and opacity can be retained after reducing basis weight as much as 10 gsm i.e., from 70 gsm to 60 gsm . A thesis submitted in partial fulfillment of the requirements for the d egree of M aster of Science in Pulp and Paper Technology Thesis (M.Sci.) - Asian Institute of Technology, 2011 Paper coatings Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B03697 http://203.159.5.9/ait-thesis/detail.php?q=B03697 171204 20260818090852.0