diff --git a/jolt-core/clojure/core/50-io.clj b/jolt-core/clojure/core/50-io.clj
index 733c3b0..aceff06 100644
--- a/jolt-core/clojure/core/50-io.clj
+++ b/jolt-core/clojure/core/50-io.clj
@@ -156,3 +156,24 @@
                         (if (keyword? t) t (type x)))))
 
 (defmethod print-dup :default [o w] (print-method o w))
+
+;; Cold tagged-type renderings, migrated from the host renderer (the hot
+;; types — numbers, strings, symbols, collections — stay native). Each is the
+;; exact output the host branch produced.
+(defmethod print-method :jolt/uuid [u w]
+  (.write w (str "#uuid \"" (get u :str) "\""))
+  nil)
+
+(defmethod print-method :jolt/regex [re w]
+  (.write w (str "#\"" (get re :source) "\""))
+  nil)
+
+;; a transient's get IS the dispatched collection lookup — read the wrapper's
+;; own :kind field with the host accessor (same trap as sorted colls).
+(defmethod print-method :jolt/transient [t w]
+  (.write w (str "#<transient " (name (jolt.host/ref-get t :kind)) ">"))
+  nil)
+
+(defmethod print-method :jolt/chan [c w]
+  (.write w "#<channel>")
+  nil)
diff --git a/src/jolt/core.janet b/src/jolt/core.janet
index d1102a3..571bd98 100644
--- a/src/jolt/core.janet
+++ b/src/jolt/core.janet
@@ -1560,13 +1560,9 @@
                              10 "newline" 32 "space" 9 "tab" 13 "return"
                              12 "formfeed" 8 "backspace" 0 "nul"
                              (char->string v))))
-      (regex? v) (do (buffer/push-string buf "#\"") (buffer/push-string buf (v :source)) (buffer/push-string buf "\""))
       (number? v) (buffer/push-string buf (fmt-number v))
       (and (struct? v) (= :symbol (v :jolt/type)))
         (buffer/push-string buf (if (v :ns) (string (v :ns) "/" (v :name)) (v :name)))
-      (and (struct? v) (= :jolt/uuid (v :jolt/type)))
-        (do (buffer/push-string buf "#uuid \"") (buffer/push-string buf (v :str))
-            (buffer/push-string buf "\""))
       (and (struct? v) (= :jolt/inst (v :jolt/type)))
         (do (buffer/push-string buf "#inst \"") (buffer/push-string buf (inst->rfc3339 v))
             (buffer/push-string buf "\""))
@@ -1581,8 +1577,6 @@
       (lazy-seq? v) (pr-render-seq buf (realize-for-iteration v) "(" ")")
       (set? v) (pr-render-seq buf (phs-seq v) "#{" "}")
       (phm? v) (pr-render-pairs buf (phm-entries v))
-      (core-transient? v) (buffer/push-string buf (string "#<transient " (v :kind) ">"))
-      (and (table? v) (= :jolt/chan (get v :jolt/type))) (buffer/push-string buf "#<channel>")
       (pvec? v) (pr-render-seq buf (pv->array v) "[" "]")
       (plist? v) (pr-render-seq buf (pl->array v) "(" ")")
       (and (table? v) (get v :jolt/deftype))
@@ -1597,6 +1591,15 @@
       (tuple? v) (pr-render-seq buf v "[" "]")
       # mutable mode: arrays are vectors -> print with [] (else lists -> ())
       (array? v) (if mutable? (pr-render-seq buf v "[" "]") (pr-render-seq buf v "(" ")"))
+      # Any remaining TAGGED value dispatches through print-method when the
+      # hook is wired: the io tier owns the cold renderings (uuid, regex,
+      # transient, channel — branches that used to live here), and user
+      # defmethods on any :jolt/* tag fire from inside nested values. Before
+      # the overlay loads (init-time error messages) these fall through to
+      # the raw pairs view below.
+      (and print-method-cb (get v :jolt/type)
+           (print-method-cb v (fn [piece] (buffer/push-string buf piece))))
+        nil
       (struct? v) (pr-render-pairs buf (pairs v))
       (table? v) (pr-render-pairs buf (pairs v))
       true (buffer/push-string buf (string v)))))
diff --git a/test/spec/io-spec.janet b/test/spec/io-spec.janet
index c16cc4b..6a2b138 100644
--- a/test/spec/io-spec.janet
+++ b/test/spec/io-spec.janet
@@ -95,3 +95,20 @@
    "(let [w (StringWriter.)] (.write w \"a\") (.append w \\b) (.toString w))"]
   ["methods table inspectable" "true"
    "(do (defrecord Pt [x y]) (defmethod print-method (quote user.Pt) [r w] r) (contains? (methods print-method) (quote user.Pt)))"])
+
+# Cold tagged-type printing now lives in io-tier defmethods (the host
+# renderer dispatches any remaining :jolt/* tagged value through the
+# print-method hook). Outputs unchanged from the old host branches; any
+# tagged type is now user-overridable, atoms included.
+(defspec "io / cold tagged types via print-method"
+  ["uuid"           "\"#uuid \\\"b6883c0a-0342-4007-9966-bc2dfa6b109e\\\"\""
+   "(pr-str (parse-uuid \"b6883c0a-0342-4007-9966-bc2dfa6b109e\"))"]
+  ["uuid nested"    "\"[#uuid \\\"b6883c0a-0342-4007-9966-bc2dfa6b109e\\\"]\""
+   "(pr-str [(parse-uuid \"b6883c0a-0342-4007-9966-bc2dfa6b109e\")])"]
+  ["regex"          "\"#\\\"a+b\\\"\""  "(pr-str #\"a+b\")"]
+  ["transient vector" "\"#<transient vector>\"" "(pr-str (transient [1]))"]
+  ["transient map"  "\"#<transient map>\""      "(pr-str (transient {:a 1}))"]
+  ["atom override fires nested" "\"{:a #atom[7]}\""
+   "(do (defmethod print-method :jolt/atom [a w] (.write w (str \"#atom[\" (deref a) \"]\"))) (pr-str {:a (atom 7)}))"]
+  ["uuid through str unchanged" "\"b6883c0a-0342-4007-9966-bc2dfa6b109e\""
+   "(str (parse-uuid \"b6883c0a-0342-4007-9966-bc2dfa6b109e\"))"])