graph.plotAreaFrame.borderLineStyle = nil;    // don't draw a border

CPLineStyle *borderLineStyle = [CPLineStyle lineStyle];
borderLineStyle.lineColor = [CPColor whiteColor];
borderLineStyle.lineWidth = 1.0;

graph.plotArea.borderLineStyle = borderLineStyle;

graph.paddingLeft = 0;
graph.paddingRight = 0;
graph.paddingTop = 0;
graph.paddingBottom = 0;
graph.plotAreaFrame.borderWidth = 0;
graph.plotAreaFrame.cornerRadius = 0;

graph.plotAreaFrame.borderLineStyle = nil;

CPTGraph *graph = [[CPTXYGraph alloc] initWithFrame:hostView.bounds];

// Set padding for plot area
[graph applyTheme:[CPTTheme themeNamed:kCPTPlainWhiteTheme]];
graph.plotAreaFrame.borderLineStyle = nil;