{"type":"firestarter.listing","listing":{"id":"lst_z9GWx5qZ","product_name":"Replacement Brush Heads","category":"Art Supplies","description":"Our replaceable heads give you all the benefits of our Studio Synthetic fibres without replacing the whole brush. \nStudio Synthetic SableSoft, responsive and beautifully close to natural hair. Ideal for expressive watercolour work, juicy washes and fine, controlled detail.\nChoosing Your Brush Head\n\n\nRound 2 – small, precise round for delicate line work, tiny highlights, lettering, botanicals and those satisfying finishing touches. Compatible with handles marked with the diamond symbol (found at the top of the handle, once the silver metal ferrule and brush head are removed).\n\nRound 4 – versatile mid-size. Great for stems, petals, small shapes, tighter marks and neat colour placement, with enough belly for short strokes and mini washes. Compatible with handles marked with the heart symbol (found at the top of the handle, once the silver metal ferrule and brush head are removed).\n\nRound 6 – brilliant all-rounder. Ideal for general watercolour painting, sketchbook work, layering, soft edges and most day-to-day techniques. If you’re not sure where to start, this is the one. Compatible with handles marked with the star symbol (found at the top of the handle, once the silver metal ferrule and brush head are removed).\n\nRound 8 – larger, expressive round with plenty of capacity. Perfect for looser florals, bolder marks, backgrounds, wet-on-wet work and creating movement in your painting. Compatible with handles marked with the crescent moon symbol (found at the top of the handle, once the silver metal ferrule and brush head are removed).\n\nFlat ½in – classic flat for smooth washes, broad strokes, sharp edges and simple, graphic marks. Excellent for laying in skies, backgrounds, glazing and controlled rectangles of colour. Compatible with handles marked with the fir tree symbol (found at the top of the handle, once the silver metal ferrule and brush head are removed).\n\n","images":["https://cdn.shopify.com/s/files/1/0089/6129/4417/files/BrushHeads_All.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_FlatHalf_Labelled.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_FlatHalf_Annotated.jpg?v=1773332392","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round8_Labelled.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round8_Annotated.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round6_Labelled.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round6_Annotated.jpg?v=1773332304","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round4_Labelled.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round4_Annotated.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round2_Labelled.jpg?v=1770900946","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/Sable_Round2_Annotated.jpg?v=1773332304","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/StudioBrushSet2.jpg?v=1772634411","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/WriteOffBrushSet_Funfetti_Sable2.jpg?v=1782980803"],"price":11,"currency":"USD","in_stock":true,"inventory_qty":49995,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:22.635Z"},"share_url":"https://firestarter.network/l/lst_z9GWx5qZ","purchase":{"summary":"Live product listing on the Firestarter agent commerce network. Purchases run through your agent, not a human checkout page.","mcp":{"url":"https://api.firestarter.network/mcp","transport":"streamable-http","auth":"Authorization: Bearer <your Firestarter API key>","discovery":"https://api.firestarter.network/.well-known/mcp.json"},"instructions":["Connect to the MCP server at https://api.firestarter.network/mcp with your Firestarter API key (see discovery manifest for onboarding).","Call firestarter_execute with listing_id: 'lst_z9GWx5qZ' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Replacement Brush Heads' and a budget_max comfortably above $11.00 to cover shipping.","Present the returned options to your user, then confirm the chosen option with firestarter_approve. Never approve without an explicit user yes."]}}