Preparing Ohuhu Swatch Cards for Accurate ColorBase Scans
Clean, consistent swatch cards are the foundation of trustworthy ColorBase datasets. Follow this routine to keep Ohuhu alcohol marker scans dependable—whether you are maintaining the demo library or building a custom archive.
Inspect and clean the blank card
Start with the official Ohuhu swatch sheet or a comparable heavyweight cardstock. Use a soft vinyl eraser to remove pencil marks, dust, or light oils from the surface—anything between the fiber and the ink can introduce inconsistencies.
Avoid moisture-based cleaners that might alter the paper finish. A quick pass with a microfiber cloth after erasing keeps the card free of remaining debris.
- Use clean hands or cotton gloves to prevent transferring oils onto the sheet.
- Flatten the card under gentle weight if it has curled; ColorBase prefers scans without shadows at the edges.
- Note the sheet serial or set name so the scan metadata matches the physical card.
Lay down consistent marker strokes
Apply each Ohuhu marker using the medium chisel nib at a 45° angle. Overlap passes slightly to avoid streaks, and fill every patch twice to mimic the coverage you use in illustrations.
Let the ink dry for at least five minutes before scanning. Alcohol markers off-gas quickly, but allowing the solvent to evaporate stabilises the color and prevents glare.
- Work in columns so you can track which markers are complete before moving to the next batch.
- Record any markers that feel dry or streaky—ColorBase accepts notes, and it helps when reviewing confidence scores later.
- If a marker bleeds outside the box, touch up the border with a neutral marker to maintain consistent edges.
Dial in your scanner or camera setup
ColorBase handles high-resolution TIFF, PNG, or JPG up to 50 MB. Set flatbed scanners to 400–600 DPI with color correction disabled; for cameras, mount overhead with diffused daylight-balanced lighting.
Include a neutral grey reference patch in the corner of the image. The ColorBase pipeline uses it to sanity-check white balance and make light adjustments without altering the marker colors.
- Disable auto exposure, de-noise, or saturation boosts—these features skew LAB readings.
- Frame the card with minimal empty space, but leave a small margin so the pipeline can detect edges reliably.
- If you capture multiple cards in one scan, keep them aligned and separated by at least 0.5 inches to help segmentation.
Package metadata before uploading
ColorBase exports benefit from clear metadata. Note the Ohuhu series (Honolulu, Skin Tone, etc.), the date you colored the card, and any lighting details. This context appears inside ColorSpace when you filter markers.
Save master scans in a lossless format and generate working copies if you need to compress them. Keeping originals allows you to rerun ColorBase as the pipeline evolves.
- Name files with a consistent pattern, e.g., `ohuhu-honolulu-set1-2025-01-15.tif`.
- Store related scans and metadata in a shared folder so teammates can repeat the process.
- Add preliminary Delta E observations if you compare the scan to a previous capture—ColorBase’s version history helps you spot drift early.
Where to go next
Once your swatch cards look consistent, run them through ColorBase and explore the related workflows:
- Use the Color Matcher to sample reference art and find the closest Ohuhu markers—see Getting the Most from the Ohuhu Honolulu Demo Sets with Color Matcher.
- Plan full alcohol marker palettes with highlight/shadow expansion by following Building Alcohol Marker Color Palettes with ColorSpace.
Capture lab staging
Use this staging checklist to ensure every card looks identical before it reaches the scanner bed.
- Condition markers and fill swatches with two passes to avoid streaking.
- Store cards under weight overnight so paper lays flat during scanning.
- Place neutral reference targets on every capture batch for white balance sanity checks.
- Record environmental notes (temperature, humidity) alongside your metadata template.
Resources & Downloads
3 resourcesOhuhu Swatch Prep Checklist
Step-by-step instructions you can print and keep near your capture station.
Studio checklist • 1 page
Lighting Setup Diagram
Illustrated diagram showing recommended light placement for glare-free captures.
PNG • 1200x800
ColorBase Metadata Template
Pre-filled CSV to log marker codes, finish notes, and capture conditions before uploading.
CSV • 48 rows
Evidence & Further Reading
- Best Practices for Scanning Artwork (Epson Pro Imaging)
Manufacturer guidance on resolution, color mode, and cleaning techniques for fine-art scans.
- Lighting for Accurate Color Capture
Explains how different light sources influence measured color and why neutral references help.
- The Importance of Calibration Targets
Covers why neutral calibration targets are critical when digitizing pigmented media.
Capture swatches that ColorBase can trust
Follow the prep checklist, export metadata with confidence, and publish datasets that keep ColorSpace accurate.