diff --git a/src/backend/d3d12/BlendStateD3D12.cpp b/src/backend/d3d12/BlendStateD3D12.cpp
index bd58f9c132..da1e1fd9a8 100644
--- a/src/backend/d3d12/BlendStateD3D12.cpp
+++ b/src/backend/d3d12/BlendStateD3D12.cpp
@@ -15,11 +15,95 @@
 #include "backend/d3d12/BlendStateD3D12.h"
 
 #include "backend/d3d12/D3D12Backend.h"
+#include "common/Assert.h"
 
 namespace backend {
 namespace d3d12 {
 
+    namespace {
+        D3D12_BLEND D3D12Blend(nxt::BlendFactor factor) {
+            switch(factor) {
+                case nxt::BlendFactor::Zero:
+                    return D3D12_BLEND_ZERO;
+                case nxt::BlendFactor::One:
+                    return D3D12_BLEND_ONE;
+                case nxt::BlendFactor::SrcColor:
+                    return D3D12_BLEND_SRC_COLOR;
+                case nxt::BlendFactor::OneMinusSrcColor:
+                    return D3D12_BLEND_INV_SRC_COLOR;
+                case nxt::BlendFactor::SrcAlpha:
+                    return D3D12_BLEND_SRC_ALPHA;
+                case nxt::BlendFactor::OneMinusSrcAlpha:
+                    return D3D12_BLEND_INV_SRC_ALPHA;
+                case nxt::BlendFactor::DstColor:
+                    return D3D12_BLEND_DEST_COLOR;
+                case nxt::BlendFactor::OneMinusDstColor:
+                    return D3D12_BLEND_INV_DEST_COLOR;
+                case nxt::BlendFactor::DstAlpha:
+                    return D3D12_BLEND_DEST_ALPHA;
+                case nxt::BlendFactor::OneMinusDstAlpha:
+                    return D3D12_BLEND_INV_DEST_ALPHA;
+                case nxt::BlendFactor::SrcAlphaSaturated:
+                    return D3D12_BLEND_SRC_ALPHA_SAT;
+                case nxt::BlendFactor::BlendColor:
+                    return D3D12_BLEND_BLEND_FACTOR;
+                case nxt::BlendFactor::OneMinusBlendColor:
+                    return D3D12_BLEND_INV_BLEND_FACTOR;
+                case nxt::BlendFactor::Src1Color:
+                    return D3D12_BLEND_SRC1_COLOR;
+                case nxt::BlendFactor::OneMinusSrc1Color:
+                    return D3D12_BLEND_INV_SRC1_COLOR;
+                case nxt::BlendFactor::Src1Alpha:
+                    return D3D12_BLEND_SRC1_ALPHA;
+                case nxt::BlendFactor::OneMinusSrc1Alpha:
+                    return D3D12_BLEND_INV_SRC1_ALPHA;
+                default:
+                    UNREACHABLE();
+            }
+        }
+
+        D3D12_BLEND_OP D3D12BlendOperation(nxt::BlendOperation operation) {
+            switch(operation) {
+                case nxt::BlendOperation::Add:
+                    return D3D12_BLEND_OP_ADD;
+                case nxt::BlendOperation::Subtract:
+                    return D3D12_BLEND_OP_SUBTRACT;
+                case nxt::BlendOperation::ReverseSubtract:
+                    return D3D12_BLEND_OP_REV_SUBTRACT;
+                case nxt::BlendOperation::Min:
+                    return D3D12_BLEND_OP_MIN;
+                case nxt::BlendOperation::Max:
+                    return D3D12_BLEND_OP_MAX;
+                default:
+                    UNREACHABLE();
+            }
+        }
+
+        uint8_t D3D12RenderTargetWriteMask(nxt::ColorWriteMask colorWriteMask) {
+            static_assert(static_cast<D3D12_COLOR_WRITE_ENABLE>(nxt::ColorWriteMask::Red) == D3D12_COLOR_WRITE_ENABLE_RED, "ColorWriteMask values must match");
+            static_assert(static_cast<D3D12_COLOR_WRITE_ENABLE>(nxt::ColorWriteMask::Green) == D3D12_COLOR_WRITE_ENABLE_GREEN, "ColorWriteMask values must match");
+            static_assert(static_cast<D3D12_COLOR_WRITE_ENABLE>(nxt::ColorWriteMask::Blue) == D3D12_COLOR_WRITE_ENABLE_BLUE, "ColorWriteMask values must match");
+            static_assert(static_cast<D3D12_COLOR_WRITE_ENABLE>(nxt::ColorWriteMask::Alpha) == D3D12_COLOR_WRITE_ENABLE_ALPHA, "ColorWriteMask values must match");
+            return static_cast<uint8_t>(colorWriteMask);
+        }
+    }
+
     BlendState::BlendState(BlendStateBuilder* builder) : BlendStateBase(builder) {
+        auto& info = GetBlendInfo();
+        blendDesc.BlendEnable = info.blendEnabled;
+        blendDesc.SrcBlend = D3D12Blend(info.colorBlend.srcFactor);
+        blendDesc.DestBlend = D3D12Blend(info.colorBlend.dstFactor);
+        blendDesc.BlendOp = D3D12BlendOperation(info.colorBlend.operation);
+        blendDesc.SrcBlendAlpha = D3D12Blend(info.alphaBlend.srcFactor);
+        blendDesc.DestBlendAlpha = D3D12Blend(info.alphaBlend.dstFactor);
+        blendDesc.BlendOpAlpha = D3D12BlendOperation(info.alphaBlend.operation);
+        blendDesc.RenderTargetWriteMask = D3D12RenderTargetWriteMask(info.colorWriteMask);
+        blendDesc.LogicOpEnable = false;
+        blendDesc.LogicOp = D3D12_LOGIC_OP_NOOP;
+    }
+
+    const D3D12_RENDER_TARGET_BLEND_DESC& BlendState::GetD3D12BlendDesc() const {
+        return blendDesc;
     }
 
 }
diff --git a/src/backend/d3d12/BlendStateD3D12.h b/src/backend/d3d12/BlendStateD3D12.h
index 57eab15dcf..315cb6f34a 100644
--- a/src/backend/d3d12/BlendStateD3D12.h
+++ b/src/backend/d3d12/BlendStateD3D12.h
@@ -17,12 +17,19 @@
 
 #include "backend/BlendState.h"
 
+#include "backend/d3d12/d3d12_platform.h"
+
 namespace backend {
 namespace d3d12 {
 
     class BlendState : public BlendStateBase {
         public:
             BlendState(BlendStateBuilder* builder);
+
+            const D3D12_RENDER_TARGET_BLEND_DESC& GetD3D12BlendDesc() const;
+
+        private:
+            D3D12_RENDER_TARGET_BLEND_DESC blendDesc;
     };
 
 }
diff --git a/src/backend/metal/BlendStateMTL.h b/src/backend/metal/BlendStateMTL.h
index 27c3e4358d..cef5ad6aec 100644
--- a/src/backend/metal/BlendStateMTL.h
+++ b/src/backend/metal/BlendStateMTL.h
@@ -17,12 +17,15 @@
 
 #include "backend/BlendState.h"
 
+#import <Metal/Metal.h>
 namespace backend {
 namespace metal {
 
     class BlendState : public BlendStateBase {
         public:
             BlendState(BlendStateBuilder* builder);
+
+            void ApplyBlendState(MTLRenderPipelineColorAttachmentDescriptor* descriptor) const;
     };
 
 }
diff --git a/src/backend/metal/BlendStateMTL.mm b/src/backend/metal/BlendStateMTL.mm
index d0aaece97d..ade6ed8037 100644
--- a/src/backend/metal/BlendStateMTL.mm
+++ b/src/backend/metal/BlendStateMTL.mm
@@ -19,8 +19,86 @@
 namespace backend {
 namespace metal {
 
+    namespace {
+
+        MTLBlendFactor MetalBlendFactor(nxt::BlendFactor factor, bool alpha) {
+            switch(factor) {
+                case nxt::BlendFactor::Zero:
+                    return MTLBlendFactorZero;
+                case nxt::BlendFactor::One:
+                    return MTLBlendFactorOne;
+                case nxt::BlendFactor::SrcColor:
+                    return MTLBlendFactorSourceColor;
+                case nxt::BlendFactor::OneMinusSrcColor:
+                    return MTLBlendFactorOneMinusSourceColor;
+                case nxt::BlendFactor::SrcAlpha:
+                    return MTLBlendFactorSourceAlpha;
+                case nxt::BlendFactor::OneMinusSrcAlpha:
+                    return MTLBlendFactorOneMinusSourceAlpha;
+                case nxt::BlendFactor::DstColor:
+                    return MTLBlendFactorDestinationColor;
+                case nxt::BlendFactor::OneMinusDstColor:
+                    return MTLBlendFactorOneMinusDestinationColor;
+                case nxt::BlendFactor::DstAlpha:
+                    return MTLBlendFactorDestinationAlpha;
+                case nxt::BlendFactor::OneMinusDstAlpha:
+                    return MTLBlendFactorOneMinusDestinationAlpha;
+                case nxt::BlendFactor::SrcAlphaSaturated:
+                    return MTLBlendFactorSourceAlphaSaturated;
+                case nxt::BlendFactor::BlendColor:
+                    return alpha ? MTLBlendFactorBlendAlpha : MTLBlendFactorBlendColor;
+                case nxt::BlendFactor::OneMinusBlendColor:
+                    return alpha ? MTLBlendFactorOneMinusBlendAlpha : MTLBlendFactorOneMinusBlendColor;
+                case nxt::BlendFactor::Src1Color:
+                    return MTLBlendFactorSource1Color;
+                case nxt::BlendFactor::OneMinusSrc1Color:
+                    return MTLBlendFactorOneMinusSource1Color;
+                case nxt::BlendFactor::Src1Alpha:
+                    return MTLBlendFactorSource1Alpha;
+                case nxt::BlendFactor::OneMinusSrc1Alpha:
+                    return MTLBlendFactorOneMinusSource1Alpha;
+            }
+        }
+
+        MTLBlendOperation MetalBlendOperation(nxt::BlendOperation operation) {
+            switch(operation) {
+                case nxt::BlendOperation::Add:
+                    return MTLBlendOperationAdd;
+                case nxt::BlendOperation::Subtract:
+                    return MTLBlendOperationSubtract;
+                case nxt::BlendOperation::ReverseSubtract:
+                    return MTLBlendOperationReverseSubtract;
+                case nxt::BlendOperation::Min:
+                    return MTLBlendOperationMin;
+                case nxt::BlendOperation::Max:
+                    return MTLBlendOperationMax;
+            }
+        }
+
+        MTLColorWriteMask MetalColorWriteMask(nxt::ColorWriteMask colorWriteMask) {
+            return (
+                ((colorWriteMask & nxt::ColorWriteMask::Red) != nxt::ColorWriteMask::None ? MTLColorWriteMaskRed : MTLColorWriteMaskNone) |
+                ((colorWriteMask & nxt::ColorWriteMask::Green) != nxt::ColorWriteMask::None ? MTLColorWriteMaskGreen : MTLColorWriteMaskNone) |
+                ((colorWriteMask & nxt::ColorWriteMask::Blue) != nxt::ColorWriteMask::None ? MTLColorWriteMaskBlue : MTLColorWriteMaskNone) |
+                ((colorWriteMask & nxt::ColorWriteMask::Alpha) != nxt::ColorWriteMask::None ? MTLColorWriteMaskAlpha : MTLColorWriteMaskNone)
+            );
+        }
+
+    }
+
     BlendState::BlendState(BlendStateBuilder* builder) : BlendStateBase(builder) {
     }
 
+    void BlendState::ApplyBlendState(MTLRenderPipelineColorAttachmentDescriptor* descriptor) const {
+        auto& info = GetBlendInfo();
+        descriptor.blendingEnabled = info.blendEnabled;
+        descriptor.sourceRGBBlendFactor = MetalBlendFactor(info.colorBlend.srcFactor, false);
+        descriptor.destinationRGBBlendFactor = MetalBlendFactor(info.colorBlend.dstFactor, false);
+        descriptor.rgbBlendOperation = MetalBlendOperation(info.colorBlend.operation);
+        descriptor.sourceAlphaBlendFactor = MetalBlendFactor(info.alphaBlend.srcFactor, true);
+        descriptor.destinationAlphaBlendFactor = MetalBlendFactor(info.alphaBlend.dstFactor, true);
+        descriptor.alphaBlendOperation = MetalBlendOperation(info.alphaBlend.operation);
+        descriptor.writeMask = MetalColorWriteMask(info.colorWriteMask);
+    }
 }
 }