I draw text throw TextPaint on Canvas. And in some cases it looks terible:
240*320 API 7

240*320 API 7

240*320 API 15

In some cases good:
720*1280 API 15

I use:
TextPaint paint = new TextPaint();
paint.setTextSize(height/20);
canvas.drawText("Just text", x, y, paint);
What do I wrong?