Open the PDF in { -brand-name-firefox }. Click the Draw icon to choose a color, thickness and opacity before then being able to draw on the document. It probably won’t be any messier than your usual signature!
在 { -brand-name-firefox } 中打开 PDF 文件，点击“绘图”图标，选择颜色、粗细、不透明度后，即可在文档上绘图。操作起来大概不比您的签名复杂！