A light emitting diode, LED, filament lamp providing LED filament lamp light and comprising at least one LED filament having a LED filament length extending from a first end to a second end, wherein the at least one LED filament provides LED filament light and comprises: - an array of a plurality of LEDs providing LED light and extending along the LED filament length, and - an encapsulant at least partially enclosing the plurality of LEDs, wherein the encapsulant comprises a light scattering material; and - wherein in the direction from the first end to the second end at least one of (i) the thickness (T L) of the encapsulant, and (ii) the concentration (C L) of the light scattering material in the encapsulant, along the LED filament length increases over at least two adjacent first LEDs and decreases over at least two adjacent second LEDs different from the at least two adjacent first LEDs, and - wherein the thickness (T L) and/or concentration (C L) firstly increases and secondly decreases at least along a portion of the LED filament length, - wherein the LED filament comprises a plurality of subsequent increases and decreases in thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant forming a plurality of maxima in said thicknesses (T L) and/or said concentrations (C L) along the LED filament length, and - wherein the thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant of at least three maxima are different; - wherein said increase and/or decrease in thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant is gradual; - wherein at least one of the thickness (T L) of the encapsulant and the concentration (C L) of the light scattering material in the encapsulant increases and/or decreases non-linearly; - wherein (i) the maxima have a maxima height and between the maxima are minima which have a minima height, the maxima height is at least 1.7 times the minima height, and/or (ii) the maxima have a maxima concentration and between the maxima there are minima which have a minima concentration, the maxima concentration is at least 1.7 times the minima concentration. - an array of a plurality of LEDs providing LED light and extending along the LED filament length, and - an encapsulant at least partially enclosing the plurality of LEDs, wherein the encapsulant comprises a light scattering material; and - wherein in the direction from the first end to the second end at least one of (i) the thickness (T L) of the encapsulant, and (ii) the concentration (C L) of the light scattering material in the encapsulant, along the LED filament length increases over at least two adjacent first LEDs and decreases over at least two adjacent second LEDs different from the at least two adjacent first LEDs, and (i) the thickness (T L) of the encapsulant, and (ii) the concentration (C L) of the light scattering material in the encapsulant, along the LED filament length increases over at least two adjacent first LEDs and decreases over at least two adjacent second LEDs different from the at least two adjacent first LEDs, and - wherein the thickness (T L) and/or concentration (C L) firstly increases and secondly decreases at least along a portion of the LED filament length, - wherein the LED filament comprises a plurality of subsequent increases and decreases in thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant forming a plurality of maxima in said thicknesses (T L) and/or said concentrations (C L) along the LED filament length, and - wherein the thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant of at least three maxima are different; - wherein said increase and/or decrease in thickness (T L) of the encapsulant and/or concentration (C L) of the light scattering material in the encapsulant is gradual; - wherein at least one of the thickness (T L) of the encapsulant and the concentration (C L) of the light scattering material in the encapsulant increases and/or decreases non-linearly; - wherein (i) the maxima have a maxima height and between the maxima are minima which have a minima height, the maxima height is at least 1.7 times the minima height, and/or (ii) the maxima have a maxima concentration and between the maxima there are minima which have a minima concentration, the maxima concentration is at least 1.7 times the minima concentration.