Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Tone (musical instrument) their tone. These may include equalization controls (such as the tone controls on electric guitars, basses, and amplifiers), "gain, drive, or fuzz" controls, reverb, etc. Electronic keyboards and synthesizers typically have multiple patches that can be selected to make the instrument produce a different timbre. Timbre Tone (musical instrument) Tone and sound are terms used by musicians and related professions to refer to the audible characteristics of a player's sound. Tone is the product of all influences on what can be heard by the listener, including the characteristics of the instrument itself, differences in playing technique (e.g. embouchure for woodwind