diff --git a/src/basic_recipes/basic_recipes.jl b/src/basic_recipes/basic_recipes.jl
index cabba5b07..6d4bec2a7 100644
--- a/src/basic_recipes/basic_recipes.jl
+++ b/src/basic_recipes/basic_recipes.jl
@@ -779,7 +779,7 @@ function plot!(plot::T) where T <: Union{Contour, Contour3d}
 end
 
 function data_limits(x::Contour{<: Tuple{X, Y, Z}}) where {X, Y, Z}
-    xyz_boundingbox(transform_func(x), to_value.((x[1], x[2]))...)
+    return xyz_boundingbox(transform_func(x), to_value.((x[1], x[2]))...)
 end
 
 """
diff --git a/src/conversions.jl b/src/conversions.jl
index 2885a75ca..fd715ae32 100644
--- a/src/conversions.jl
+++ b/src/conversions.jl
@@ -267,6 +267,7 @@ float32type(::Type{<: Colorant}) = RGBA{Float32}
 float32type(x::AbstractArray{T}) where T = float32type(T)
 float32type(x::T) where T = float32type(T)
 el32convert(x::AbstractArray) = elconvert(float32type(x), x)
+el32convert(x::Observable) = lift(el32convert, x)
 el32convert(x) = convert(float32type(x), x)
 
 function el32convert(x::AbstractArray{T, N}) where {T<:Union{Missing, <: Number}, N}
@@ -551,6 +552,11 @@ end
 #                            Attribute conversions                             #
 ################################################################################
 
+convert_attribute(p, ::key"highclip") = to_color(p)
+convert_attribute(p::Nothing, ::key"highclip") = p
+convert_attribute(p, ::key"lowclip") = to_color(p)
+convert_attribute(p::Nothing, ::key"lowclip") = p
+convert_attribute(p, ::key"nan_color") = to_color(p)
 
 struct Palette{N}
    colors::SArray{Tuple{N},RGBA{Float32},1,N}
diff --git a/src/interfaces.jl b/src/interfaces.jl
index 9cfc132c6..8e76bb13e 100644
--- a/src/interfaces.jl
+++ b/src/interfaces.jl
@@ -52,6 +52,8 @@ $(ATTRIBUTES)
         colormap = [:black, :white],
         interpolate = true,
         fxaa = false,
+        lowclip = nothing,
+        highclip = nothing,
     )
 end
 
@@ -120,8 +122,9 @@ $(ATTRIBUTES)
         color = nothing,
         colormap = :viridis,
         shading = true,
-        interpolate = true,
         fxaa = true,
+        lowclip = nothing,
+        highclip = nothing,
     )
 end
 
@@ -292,6 +295,7 @@ function calculated_attributes!(::Type{<: Union{Heatmap, Image}}, plot)
     plot[:color] = plot[3]
     color_and_colormap!(plot)
 end
+
 function calculated_attributes!(::Type{<: Surface}, plot)
     colors = plot[3]
     if haskey(plot, :color)
diff --git a/test/simple.jl b/test/simple.jl
index e15d3960c..17db3e3f8 100644
--- a/test/simple.jl
+++ b/test/simple.jl
@@ -2,10 +2,28 @@ using AbstractPlotting
 using GLMakie
 using GeometryBasics
 using Observables
-using FileIO
 using GeometryBasics: Pyramid
 using PlotUtils
+using MeshIO, FileIO
+
+## Some helpers
+data_2d = AbstractPlotting.peaks()
+args_2d = (-10..10, -10..10, data_2d)
+
+function n_times(f, n=10, interval=0.05)
+    obs = Observable(f(1))
+    @async for i in 2:n
+        try
+            obs[] = f(i)
+            sleep(interval)
+        catch e
+            @warn "Error!" exception=CapturedException(e, Base.catch_backtrace())
+        end
+    end
+    return obs
+end
 
+## Scatter
 scatter(1:4, color=:red)
 scatter(1:4, marker='☼')
 scatter(1:4, marker=['☼', '◒', '◑', '◐'])
@@ -14,7 +32,7 @@ scatter(1:4, marker=rand(RGBf0, 10, 10), markersize=20px) |> display
 # TODO rotation with markersize=px
 scatter(1:4, marker='▲', markersize=0.3, rotations=LinRange(0, pi, 4)) |> display
 
-# Meshscatter
+## Meshscatter
 meshscatter(1:4, color=1:4) |> display
 
 meshscatter(1:4, color=rand(RGBAf0, 4))
@@ -23,7 +41,7 @@ meshscatter(1:4, color=:red)
 meshscatter(rand(Point3f0, 10), color=rand(RGBf0, 10))
 meshscatter(rand(Point3f0, 10), marker=Pyramid(Point3f0(0), 1f0, 1f0)) |> display
 
-# Lines
+## Lines
 positions = Point2f0.([1:4; NaN; 1:4], [1:4; NaN; 2:5])
 lines(positions)
 lines(positions, linestyle=:dot)
@@ -31,7 +49,7 @@ lines(positions, linestyle=[0.0, 1.0, 2.0, 3.0, 4.0])
 lines(positions, color=1:9)
 lines(positions, color=rand(RGBf0, 9), linewidth=4)
 
-# Linesegments
+## Linesegments
 linesegments(1:4)
 linesegments(1:4, linestyle=:dot)
 linesegments(1:4, linestyle=[0.0, 1.0, 2.0, 3.0, 4.0])
@@ -39,21 +57,21 @@ linesegments(1:4, color=1:4)
 linesegments(1:4, color=rand(RGBf0, 4), linewidth=4)
 
 
-# Surface
-data = AbstractPlotting.peaks()
-surface(-10..10, -10..10, data)
-surface(-10..10, -10..10, data, color=rand(size(data)...)) |> display
-surface(-10..10, -10..10, data, color=rand(RGBf0, size(data)...))
-surface(-10..10, -10..10, data, colormap=:magma, colorrange=(0.0, 2.0))
+## Surface
+surface(args_2d...)
+surface(args_2d..., color=rand(size(data_2d)...))
+surface(args_2d..., color=rand(RGBf0, size(data_2d)...))
+surface(args_2d..., colormap=:magma, colorrange=(-3.0, 4.0))
+surface(args_2d..., shading=false); wireframe!(args_2d..., linewidth=0.5)
 
-# Polygons
+## Polygons
 poly(decompose(Point2f0, Circle(Point2f0(0), 1f0)))
 
-# Image like!
+## Image like!
 image(rand(10, 10))
 heatmap(rand(10, 10))
 
-# Volumes
+## Volumes
 volume(rand(4, 4, 4), isovalue=0.5, isorange=0.01, algorithm=:iso) |> display
 volume(rand(4, 4, 4), algorithm=:mip)
 volume(rand(4, 4, 4), algorithm=:absorption)
@@ -62,8 +80,7 @@ volume(rand(4, 4, 4), algorithm=Int32(5)) |> display
 volume(rand(RGBAf0, 4, 4, 4), algorithm=:absorptionrgba)
 contour(rand(4, 4, 4)) |> display
 
-# Meshes
-using MeshIO, FileIO
+## Meshes
 cat = load(GLMakie.assetpath("cat.obj"))
 tex = load(GLMakie.assetpath("diffusemap.tga"));
 scren = mesh(cat, color=tex)
@@ -74,7 +91,7 @@ m = mesh([(0.0, 0.0), (0.5, 1.0), (1.0, 0.0)], color = [:red, :green, :blue],
 meshes = GeometryBasics.normal_mesh.([Sphere(Point3f0(0.5), 1), Rect(Vec3f0(1, 0, 0), Vec3f0(1))])
 mesh(meshes, color=[1, 2])
 
-# Axis
+## Axis
 scene = lines(IRect(Vec2f0(0), Vec2f0(1)))
 axis = scene[Axis]
 axis.ticks.ranges = ([0.1, 0.2, 0.9], [0.1, 0.2, 0.9])
@@ -82,29 +99,20 @@ axis.ticks.labels = (["😸", "♡", "𝕴"], ["β ÷ δ", "22", "≙"])
 scene
 
 
-# Text
+## Text
 x = text("heyllo") |> display
 
 
-# Gradients
-data = ((x, y) -> x^2 + y^2).(1:100, (1:100)')
-heatmap(data; colormap=cgrad(:RdYlBu; categorical=true), interpolate=true)
-extrema(data)
-heatmap(data; interpolate=true, colorrange=(-6.0, 7.0), highclip=:black, lowclip=:pink)
+## Colormaps
+cmap = cgrad(:RdYlBu; categorical=true);
+heatmap(args_2d...; colormap=cgrad(:RdYlBu; categorical=true), interpolate=true)
 
-# Animations
-function n_times(f, n=10, interval=0.05)
-    obs = Observable(f(1))
-    @async for i in 2:n
-        try
-            obs[] = f(i)
-            sleep(interval)
-        catch e
-            @warn "Error!" exception=CapturedException(e, Base.catch_backtrace())
-        end
-    end
-    return obs
-end
+image(args_2d...; colormap=cgrad(:RdYlBu; categorical=true), interpolate=true)
+
+s = heatmap(args_2d...; colorrange=(-4.0, 3.0), colormap=cmap, highclip=:green, lowclip=:pink, interpolate=true)
+surface(args_2d...; colorrange=(-4.0, 3.0), highclip=:green, lowclip=:pink)
+
+## Animations
 
 annotations(n_times(i-> map(j-> ("$j", Point2f0(j*30, 0)), 1:i)), textsize=20, limits=FRect2D(30, 0, 320, 50))
 scatter(n_times(i-> Point2f0.((1:i).*30, 0)), limits=FRect2D(30, 0, 320, 50), markersize=20px)
@@ -136,8 +144,7 @@ lp = map(radius, theta, phi) do r, theta, phi
 end
 
 scene = Scene()
-contour!(scene, 0..1, 0..1, 0..1, rand(10, 10, 10), levels = 2;
-ambient = la, diffuse = ld, specular = ls, shininess = shininess,lightposition = lp)
+surface!(scene, args_2d...; ambient = la, diffuse = ld, specular = ls, shininess = shininess,lightposition = lp)
 scatter!(scene, map(v -> [v], lp), color=:yellow, markersize=0.2f0)
 
 vbox(hbox(s4, s3, s2, s1, s7, s6, s5), scene) |> display
@@ -150,8 +157,12 @@ lines!(1:4, color=rand(RGBf0, 4)) |> display
 
 
 # Views
-
 x = Point2f0[(1, 1), (2, 2), (3, 2), (4, 4)]
 points = connect(x, LineFace{Int}[(1, 2), (2, 3), (3, 4)])
 linesegments(points)
 scatter(x)
+p4 = heatmap(rand(100, 100))
+
+# Interpolation
+heatmap(data_2d, interpolate=true)
+image(data_2d, interpolate=false)