用泡沫塑料制作径向对称版画
利用泡沫塑料印版制作小幅版画，体验径向对称。这种对称基于一个元素围绕中心点旋转的原理。制作印版时，我们从泡沫塑料食品托盘上裁下若干小方块（8×8 厘米）。
接下来，我们需要一张与印版尺寸相同的小正方形纸（8×8 厘米），用于规划待雕刻的图案。将这张正方形纸沿对角线对折，得到一个三角形。在该三角形纸面上，画出三条曲线、两条直线、两个或更多小圆，以及若干装饰性短划线。这些提示有助于保持图案简洁——因泡沫塑料印版不易雕刻，故不宜设计过于繁复的纹样。在纸张一半所绘的图案，需描摹至另一半，从而沿对角线获得对称图形。
将折好的纸样覆盖于印版之上，用铅笔描画图案，使泡沫塑料表面留下轻微痕迹；再用削尖的铅笔沿此痕迹深入刻划泡沫塑料表面。
为印版上色时，我们使用平头画笔，以不同方向薄而均匀地涂抹丙烯颜料。印刷过程徒手完成，无需印刷机——将泡沫塑料印版压印于白纸上即可。操作时需注意：印版上颜料不可过厚；同时应以印版一角为轴心“旋转”印版，如此方可获得径向对称的印痕。所需材料如下：
- 小型泡沫塑料印版（8×8 厘米）
- 8×8 厘米纸片
- 削尖的铅笔
- 平头画笔
- 丙烯颜料
- 绘画纸或白卡纸
- 活动时长：3 小时
作品完成后，我们观察了已使用的印版，发现它们本身非常美观！于是决定将这些彩色泡沫塑料印版组合成一幅装饰性展板：将全部印版粘贴于一张海报板上，悬挂在教室中：
另一次实验是借助电脑图像拼贴软件，创建模块化图案。所得图样十分迷人！
Prints in radial symmetry with styrofoam
Small prints made with styrofoam matrices to experience the radial symmetry. This type of symmetry is based on the principle of rotation of an element, respect to a central point. To realize the printing plate we cut out of small squares (8×8 cm) from styrofoam food trays.
Now we need a small square of paper, the same size of the printing plate, to plan the design to be engraved. The square of paper is folded in half along the diagonal. On the paper triangle thus obtained, we draw three curves lines, two straight lines, two or more small circles and some decorative dashes. These indications are useful for maintaining a certain simplicity in the drawing, since the matrix is not very easy to engrave, it is preferable not to make too intricate patterns. The design made on half of the leaflet, is traced on the second half, in order to obtain a symmetrical design on the diagonal.
Superimposing the leaflet on the printing plate, you draw the design with a pencil, in order to leave a slight trace on polystyrene. This trace is then engraved with a sharpened pencil in a deeper way into the styrofoam surface.
To put the color on the printing plate we used flat brushes, smearing a thin layer of acrylic color in different directions. Printing is done by hand without the use of press, pressing the polystyrene plate on a white sheet. We have to be careful not to put too much color on the printing plate, and to “rotate” the matrix around a corner, in this way you will get a print in radial symmetry. We need:
- small styrofoam plates 8×8 cm
- piece of paper 8×8 cm
- sharp pencil
- flat brush
- acrylic painting
- drawing paper or white card
- duration of the activity: 3 hours
At the end of the work, we have observed our printing plates used, and we found them really beautiful! So we decided to use the colored styrofoam plates to create a decorative panel. We glued all them on a poster to be hung in the classroom:
Another experiment was to create modular surfaces with a photo collage program on the computer. The patterns that we got are very charming!
