Table 1.

Formulation for each foam ink

Sample	Ingredients	pH
Ink 1	• Egg white 87.5 wt% • Honeydew extract 12.5 wt%	9.19
Ink 2	• Egg white 85.5 wt% • Honeydew extract 12.5 wt% • Xanthan gum 2 wt%	8.91
Ink 3	• Methocel F50 2 wt% • Water • Honeydew extract 12.5 wt%	8.33
Ink 4	• Foam Magic 2 wt% • Water • Honeydew extract 12.5 wt%	8.16
Ink 5	• Methocel F50 2 wt% • Foam Magic 2 wt% • Water • Honeydew extract 12.5 wt%	8.20