Photo collage
for color value check
Take photo on iPhone or iPad
Use the share tab to duplicate
Use the duplicate photo to edit and change to mono
Use the Moldiv or similar app to group them side by side for analysis, see next slide
Change to Mono
Choose 2 side by side
Select collage style
Tap to insert photos
Chose from recent photos
Match color and mono
Compare color to value!
Analysis
Using the color/value check comparisons really helped me to select the best background for the dog appliqué. The backing is quilted first then appliquéd to the backing using Monopoly invisible thread.
I also used the color/value check to find the best placement. I placed the appliqué with a touch of the ombré yellow around it .
I thank all the SMQG commenters as they opened my eyes to insights on color and value.