Image Opacity Adjuster

How globalAlpha opacity works in canvas: Opacity 0 percent maps to alpha 0 fully transparent, 50 percent to 0.5 half, 100 percent to 1 opaque. The tool draws your image to canvas with globalAlpha set to slider divided by 100, then exports PNG that keeps alpha channel for layering over colors, gradients, or video from Austin to Seattle. A 3000 by 2000 product at 40 percent becomes a ghost for text overlay, while 15 percent creates subtle watermark over $299 kits photographed 07/15/2026.

When to use 10, 30, 60, and 85 percent: Use 12 to 20 percent for watermark that deters copy but keeps product readable in Chicago and Miami shops. Use 30 to 45 percent for hero overlays where white text at 18px needs contrast on Denver trail shots. Use 60 to 75 percent for before after sliders in Seattle decks. Keep 85 to 90 percent for soft fade that still shows bag texture for New York lookbooks on 08/01/2026. Test on iPhone SE and 4K; low alpha washes out under bright Florida sun thumbnails.

Export choice, edges, and file size USA norms: PNG preserves alpha for layering; JPG flattens to white and loses transparency, so pick PNG for overlay and WebP with alpha for web under 500 KB. Feather is none; edges stay crisp at 2000 to 3000 pixels. A 12 MP Austin headshot at 40 percent exports about 1.2 MB PNG, large for Shopify, so recompress to WebP 70 quality after. For print on 10 by 8 at 300 DPI, export PNG then place in InDesign with 85 percent opacity to keep press blacks deep for $45 proof dated 06/20/2026.

Common fixes for washed text and halos: If white text over 30 percent image lacks contrast in Manhattan ads, add 40 percent black scrim behind text or lift opacity to 55 percent. Halos around Chicago cutouts come from prior JPEG fringing; clean with Background Remover before lowering opacity. Banding in Seattle gradients at 20 percent stems from 8-bit; add 2 percent noise before export. Re-check with Image Info Analyzer for 1200 by 630 OG where 35 percent overlay keeps large-card readability from Miami to New York.

Privacy, cost, and next steps: Processing is local canvas, free instantly offline with no signup required ever, no $9 to $29 SaaS watermark fee and no upload of embargoed New York assets before 09/01/2026. Preview is instant, export is one click. Pair with Background Blur for depth, Brightness Contrast for punch, and Palette Extractor for scrim color. Keep master opaque and derive 30 percent variant with MM/DD/YYYY versioning for Illinois audits.