A transparent, impact-modified composition, having a haze of less than 25 and a total white light transmission (TWLT) greater than 80 as measured by ASTM D1003 on a plaque having a thickness of 3 mm, comprising: a) 20 - 95 weight percent of a thermoplastic matrix, and b) 5 to 80 weight percent of impact modifier particles, being either i) composite particles comprising from 1-75 weight percent of one or more polymeric process aids, and from 25 to 99 weight percent of core-shell impact modifier particles, wherein said process aids and said core-shell impact modifier are physically and/or chemically attached through physical entanglements, encapsulation, van der Waals forces, hydrogen bonding, or chemical bonding; or ii) impact modifiers having a core-shell polymer structure and comprising one or more layers having a refractive index of at least 0.005 units different from the R.I. of a different layer of the core-shell polymer; wherein the difference in refractive index (R.I.) between the thermoplastic matrix and impact modifier particles is greater than 0.010 units and the refractive index is measured on a Abbe's refractometer according to ASTM-D542 and wherein the thermoplastic matrix is selected from acrylic polymer alloys comprising 40 - 95 percent by weight of acrylic polymer, and from 5-60 weight percent of a low melt viscosity polymer that has a melt flow rate of more than 10 g/10 minutes as measured by ASTM D1238 at 230°C/10.4kg of force. a) 20 - 95 weight percent of a thermoplastic matrix, and b) 5 to 80 weight percent of impact modifier particles, being either i) composite particles comprising from 1-75 weight percent of one or more polymeric process aids, and from 25 to 99 weight percent of core-shell impact modifier particles, wherein said process aids and said core-shell impact modifier are physically and/or chemically attached through physical entanglements, encapsulation, van der Waals forces, hydrogen bonding, or chemical bonding; or ii) impact modifiers having a core-shell polymer structure and comprising one or more layers having a refractive index of at least 0.005 units different from the R.I. of a different layer of the core-shell polymer; wherein the difference in refractive index (R.I.) between the thermoplastic matrix and impact modifier particles is greater than 0.010 units and the refractive index is measured on a Abbe's refractometer according to ASTM-D542 and wherein the thermoplastic matrix is selected from acrylic polymer alloys comprising 40 - 95 percent by weight of acrylic polymer, and from 5-60 weight percent of a low melt viscosity polymer that has a melt flow rate of more than 10 g/10 minutes as measured by ASTM D1238 at 230°C/10.4kg of force. i) composite particles comprising from 1-75 weight percent of one or more polymeric process aids, and from 25 to 99 weight percent of core-shell impact modifier particles, wherein said process aids and said core-shell impact modifier are physically and/or chemically attached through physical entanglements, encapsulation, van der Waals forces, hydrogen bonding, or chemical bonding; or ii) impact modifiers having a core-shell polymer structure and comprising one or more layers having a refractive index of at least 0.005 units different from the R.I. of a different layer of the core-shell polymer; wherein the difference in refractive index (R.I.) between the thermoplastic matrix and impact modifier particles is greater than 0.010 units and the refractive index is measured on a Abbe's refractometer according to ASTM-D542 and wherein the thermoplastic matrix is selected from acrylic polymer alloys comprising 40 - 95 percent by weight of acrylic polymer, and from 5-60 weight percent of a low melt viscosity polymer that has a melt flow rate of more than 10 g/10 minutes as measured by ASTM D1238 at 230°C/10.4kg of force. wherein the difference in refractive index (R.I.) between the thermoplastic matrix and impact modifier particles is greater than 0.010 units and the refractive index is measured on a Abbe's refractometer according to ASTM-D542 and wherein the thermoplastic matrix is selected from acrylic polymer alloys comprising 40 - 95 percent by weight of acrylic polymer, and from 5-60 weight percent of a low melt viscosity polymer that has a melt flow rate of more than 10 g/10 minutes as measured by ASTM D1238 at 230°C/10.4kg of force.