diff --git a/Cargo.lock b/Cargo.lock
index fc0482a..d286753 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -78,9 +78,9 @@ checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
 [[package]]
 name = "bitflags"
-version = "1.3.2"
+version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
 
 [[package]]
 name = "bytemuck"
@@ -204,9 +204,9 @@ checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
 [[package]]
 name = "png"
-version = "0.17.16"
+version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82151a2fc869e011c153adc57cf2789ccb8d9906ce52c0b39a6b5697749d7526"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
 dependencies = [
  "bitflags",
  "crc32fast",
@@ -235,7 +235,7 @@ dependencies = [
 
 [[package]]
 name = "rustitch"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
  "png",
  "thiserror",
@@ -250,7 +250,7 @@ checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
 
 [[package]]
 name = "stitch-peek"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
  "anyhow",
  "clap",
@@ -302,9 +302,9 @@ dependencies = [
 
 [[package]]
 name = "tiny-skia"
-version = "0.11.4"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83d13394d44dae3207b52a326c0c85a8bf87f1541f23b0d143811088497b09ab"
+checksum = "47ffee5eaaf5527f630fb0e356b90ebdec84d5d18d937c5e440350f88c5a91ea"
 dependencies = [
  "arrayref",
  "arrayvec",
@@ -317,9 +317,9 @@ dependencies = [
 
 [[package]]
 name = "tiny-skia-path"
-version = "0.11.4"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c9e7fc0c2e86a30b117d0462aa261b72b7a99b7ebd7deb3a14ceda95c5bdc93"
+checksum = "edca365c3faccca67d06593c5980fa6c57687de727a03131735bb85f01fdeeb9"
 dependencies = [
  "arrayref",
  "bytemuck",
diff --git a/rustitch/Cargo.toml b/rustitch/Cargo.toml
index dac3b48..af4d1d0 100644
--- a/rustitch/Cargo.toml
+++ b/rustitch/Cargo.toml
@@ -1,9 +1,12 @@
 [package]
 name = "rustitch"
-version = "0.1.0"
-edition = "2021"
+version = "0.1.1"
+edition = "2024"
 
 [dependencies]
 thiserror = "2"
-tiny-skia = "0.11"
-png = "0.17"
+tiny-skia = "0.12"
+png = "0.18"
+
+[dev-dependencies]
+png = "0.18"
diff --git a/rustitch/tests/fixtures/JLS_Gnome Barfs.PES b/rustitch/tests/fixtures/JLS_Gnome Barfs.PES
new file mode 100644
index 0000000..406786a
Binary files /dev/null and b/rustitch/tests/fixtures/JLS_Gnome Barfs.PES differ
diff --git a/rustitch/tests/fixtures/UFront.PES b/rustitch/tests/fixtures/UFront.PES
new file mode 100644
index 0000000..3ff6dc9
Binary files /dev/null and b/rustitch/tests/fixtures/UFront.PES differ
diff --git a/rustitch/tests/fixtures/UrsulaOne.PES b/rustitch/tests/fixtures/UrsulaOne.PES
new file mode 100644
index 0000000..3a97641
Binary files /dev/null and b/rustitch/tests/fixtures/UrsulaOne.PES differ
diff --git a/rustitch/tests/pes_files.rs b/rustitch/tests/pes_files.rs
new file mode 100644
index 0000000..bc84ad1
--- /dev/null
+++ b/rustitch/tests/pes_files.rs
@@ -0,0 +1,201 @@
+use std::io::Cursor;
+
+use rustitch::pes::{self, StitchCommand};
+
+const GNOME_BARFS: &[u8] = include_bytes!("fixtures/JLS_Gnome Barfs.PES");
+const URSULA_ONE: &[u8] = include_bytes!("fixtures/UrsulaOne.PES");
+const UFRONT: &[u8] = include_bytes!("fixtures/UFront.PES");
+
+// -- Header parsing ----------------------------------------------------------
+
+#[test]
+fn parse_header_gnome_barfs() {
+    let design = pes::parse(GNOME_BARFS).unwrap();
+    assert_eq!(&design.header.version, b"0100");
+}
+
+#[test]
+fn parse_header_ursula_one() {
+    let design = pes::parse(URSULA_ONE).unwrap();
+    assert_eq!(&design.header.version, b"0060");
+}
+
+#[test]
+fn parse_header_ufront() {
+    let design = pes::parse(UFRONT).unwrap();
+    assert_eq!(&design.header.version, b"0060");
+}
+
+// -- PEC color table ---------------------------------------------------------
+
+#[test]
+fn gnome_barfs_has_colors() {
+    let design = pes::parse(GNOME_BARFS).unwrap();
+    assert!(
+        design.pec_header.color_count > 0,
+        "expected at least one color"
+    );
+    assert_eq!(
+        design.pec_header.color_indices.len(),
+        design.pec_header.color_count as usize
+    );
+}
+
+#[test]
+fn ursula_one_has_colors() {
+    let design = pes::parse(URSULA_ONE).unwrap();
+    assert!(design.pec_header.color_count > 0);
+    // All color indices should be valid palette entries (0..65)
+    for &idx in &design.pec_header.color_indices {
+        assert!(
+            (idx as usize) < pes::PEC_PALETTE.len(),
+            "color index {idx} out of palette range"
+        );
+    }
+}
+
+// -- Stitch commands ---------------------------------------------------------
+
+#[test]
+fn gnome_barfs_commands_end_properly() {
+    let design = pes::parse(GNOME_BARFS).unwrap();
+    let last = design.commands.last().unwrap();
+    assert!(
+        matches!(last, StitchCommand::End),
+        "expected End command as last, got {last:?}"
+    );
+}
+
+#[test]
+fn ursula_one_commands_end_properly() {
+    let design = pes::parse(URSULA_ONE).unwrap();
+    let last = design.commands.last().unwrap();
+    assert!(
+        matches!(last, StitchCommand::End),
+        "expected End command as last, got {last:?}"
+    );
+}
+
+#[test]
+fn ufront_has_stitches() {
+    let design = pes::parse(UFRONT).unwrap();
+    let stitch_count = design
+        .commands
+        .iter()
+        .filter(|c| matches!(c, StitchCommand::Stitch { .. }))
+        .count();
+    assert!(
+        stitch_count > 100,
+        "expected many stitches, got {stitch_count}"
+    );
+}
+
+#[test]
+fn gnome_barfs_has_color_changes() {
+    let design = pes::parse(GNOME_BARFS).unwrap();
+    let changes = design
+        .commands
+        .iter()
+        .filter(|c| matches!(c, StitchCommand::ColorChange))
+        .count();
+    // Multi-color design should have at least one color change
+    assert!(changes > 0, "expected color changes, got none");
+}
+
+// -- Resolve to segments -----------------------------------------------------
+
+#[test]
+fn resolve_gnome_barfs() {
+    let design = pes::parse(GNOME_BARFS).unwrap();
+    let resolved = pes::resolve(&design).unwrap();
+
+    assert!(!resolved.segments.is_empty());
+    assert!(!resolved.colors.is_empty());
+
+    // Bounding box should be non-degenerate
+    assert!(resolved.bounds.max_x > resolved.bounds.min_x);
+    assert!(resolved.bounds.max_y > resolved.bounds.min_y);
+}
+
+#[test]
+fn resolve_ursula_one() {
+    let design = pes::parse(URSULA_ONE).unwrap();
+    let resolved = pes::resolve(&design).unwrap();
+
+    assert!(!resolved.segments.is_empty());
+    assert!(resolved.bounds.max_x > resolved.bounds.min_x);
+    assert!(resolved.bounds.max_y > resolved.bounds.min_y);
+}
+
+#[test]
+fn resolve_ufront() {
+    let design = pes::parse(UFRONT).unwrap();
+    let resolved = pes::resolve(&design).unwrap();
+
+    assert!(!resolved.segments.is_empty());
+
+    // All segment color indices should be within the resolved color list
+    let max_ci = resolved
+        .segments
+        .iter()
+        .map(|s| s.color_index)
+        .max()
+        .unwrap();
+    assert!(
+        max_ci < resolved.colors.len(),
+        "segment references color {max_ci} but only {} colors resolved",
+        resolved.colors.len()
+    );
+}
+
+// -- Full thumbnail pipeline -------------------------------------------------
+
+#[test]
+fn thumbnail_gnome_barfs_128() {
+    let png = rustitch::thumbnail(GNOME_BARFS, 128).unwrap();
+    assert_png_dimensions(&png, 128, 128);
+}
+
+#[test]
+fn thumbnail_ursula_one_256() {
+    let png = rustitch::thumbnail(URSULA_ONE, 256).unwrap();
+    assert_png_dimensions(&png, 256, 256);
+}
+
+#[test]
+fn thumbnail_ufront_64() {
+    let png = rustitch::thumbnail(UFRONT, 64).unwrap();
+    assert_png_dimensions(&png, 64, 64);
+}
+
+#[test]
+fn thumbnail_gnome_barfs_not_blank() {
+    let png = rustitch::thumbnail(GNOME_BARFS, 128).unwrap();
+    let pixels = decode_png_pixels(&png);
+    // At least some pixels should have non-zero alpha (not fully transparent)
+    let opaque_count = pixels.chunks_exact(4).filter(|px| px[3] > 0).count();
+    assert!(
+        opaque_count > 100,
+        "thumbnail looks blank, only {opaque_count} non-transparent pixels"
+    );
+}
+
+// -- Helpers -----------------------------------------------------------------
+
+fn assert_png_dimensions(png_data: &[u8], expected_w: u32, expected_h: u32) {
+    let decoder = png::Decoder::new(Cursor::new(png_data));
+    let reader = decoder.read_info().unwrap();
+    let info = reader.info();
+    assert_eq!(info.width, expected_w, "unexpected PNG width");
+    assert_eq!(info.height, expected_h, "unexpected PNG height");
+    assert_eq!(info.color_type, png::ColorType::Rgba);
+    assert_eq!(info.bit_depth, png::BitDepth::Eight);
+}
+
+fn decode_png_pixels(png_data: &[u8]) -> Vec<u8> {
+    let decoder = png::Decoder::new(Cursor::new(png_data));
+    let mut reader = decoder.read_info().unwrap();
+    let mut buf = vec![0u8; reader.output_buffer_size().unwrap()];
+    reader.next_frame(&mut buf).unwrap();
+    buf
+}
diff --git a/stitch-peek/Cargo.toml b/stitch-peek/Cargo.toml
index cf6d9cc..8885085 100644
--- a/stitch-peek/Cargo.toml
+++ b/stitch-peek/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "stitch-peek"
-version = "0.1.0"
-edition = "2021"
+version = "0.1.1"
+edition = "2024"
 
 [dependencies]
 rustitch = { path = "../rustitch" }