Polygon or Polylines to Raster comes up in gradient icon with same value min and max

Discussion created by marie-neige on Jan 24, 2014
Hi I converted few polylines and polygons layers to raster, one by one,
from one specific field to which I put only one single value to every object of the original vector. I used the same settings for all the conversions but I don,t know why some of them came up as gradient. In the layer box the icon is not a simple colored square but a gradient icon with min and max which have the same value.