Lesson Notes By Weeks and Term v3 - Senior Secondary 3
Image Production
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Image Production
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Subject: Printing Craft Practice
Class: Senior Secondary 3
Term: 2nd Term
Week: 8
Theme: Screen Printing
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
make prints from the screen. make reproduction of the design using the same screen.
This lesson focuses on the practical execution of screen printing to produce prints and subsequently reproduce designs. The core principle of screen printing is the use of a mesh screen, where a stencil blocks certain areas, allowing ink to pass through only the unblocked areas onto the substrate. 2.
1. Screen Printing Process for Initial Print Production Producing prints from a screen involves a series of sequential steps:
1. Preparation of the Screen: Screen Selection: Choose a screen with the appropriate mesh count (e.g., 60-120 mesh for textiles, 120-200 mesh for paper/fine detail). Higher mesh counts give finer detail but allow less ink flow.
Degreasing: Wash the mesh thoroughly with a degreasing agent and water to remove any oils or contaminants that could prevent stencil adhesion. Rinse thoroughly and allow to dry completely.
Stenciling: Paper Stencil Method (Simplest): For basic designs, cut the design out of strong paper or thin cardboard. Adhere this stencil to the underside of the screen using masking tape or a light adhesive spray. This method is suitable for bold, simple designs and limited print runs. Photo Emulsion Method (Common for detailed work): Coating: Apply a thin, even layer of photo emulsion to both sides of the degreased, dry screen using a scoop coater. The emulsion is light-sensitive.
Drying: Dry the coated screen horizontally in a dark, dust-free environment (e.g., a darkroom or a box with a fan).
Exposure: Place the positive film (transparency with the design) in direct contact with the emulsion side of the screen. Expose the screen to a strong UV light source (e.g., specialized exposure unit, sunlight) for a specific duration. The light hardens the exposed emulsion, while the areas covered by the design remain soft.
Washout: Gently spray water onto both sides of the screen. The unexposed (soft) emulsion in the design areas will wash away, creating the stencil.
Drying and Touch-up: Allow the screen to dry. Use a block-out medium or tape to fill any pinholes or unwanted openings in the stencil.
2. Preparation of the Printing Station: Work Surface: Ensure a clean, flat, stable printing surface (e.g., a printing table, platen). For textile printing, a platen with adhesive spray is ideal to hold the fabric in place.
Off-contact Distance: Adjust the screen frame so there is a small gap (off-contact) of about 1/8 inch (3-5mm) between the screen and the substrate when the screen is in the printing position. This allows the mesh to snap off the substrate cleanly after the squeegee pass, ensuring a crisp print.
Registration Guides: For accurate placement and multi-colour jobs, establish registration marks or guides on the printing surface. For single-colour, simply mark the position for the substrate.
3. Ink Preparation: Ink Selection: Choose the appropriate ink for the substrate (e.g., plastisol or water-based inks for fabric, solvent-based or acrylic inks for paper/PVC).
Mixing: Stir the ink thoroughly to ensure consistent viscosity and colour. Add reducers or additives if necessary to adjust viscosity, flow, or drying time, following manufacturer's instructions.
4. The Printing Process (Making the Print): Substrate Placement: Position the substrate (e.g., T-shirt, paper, banner material) onto the printing surface, aligning it with registration guides if used.
Screen Lowering: Lower the screen onto the substrate.
Ink Flooding (Optional but Recommended): Place a bead of ink across one end of the screen, just above the design. Using light pressure, pull the squeegee across the design area to 'flood' the mesh, filling the stencil openings with ink. This prevents the ink from drying in the screen and ensures a smooth first pass.
Squeegee Pass: Hold the squeegee at a consistent angle (typically 45-75 degrees) with firm, even pressure. Pull the squeegee in a single, smooth stroke across the design area, pushing the ink through the open mesh onto the substrate. The pressure and angle are critical for even ink deposition.
Screen Lifting: Carefully lift the screen, ensuring the design has transferred completely.
Substrate Removal: Remove the printed substrate.
Drying: Place the printed item in a drying rack or tunnel dryer. Textile prints often require heat curing The green screen is lowered, green ink applied, and a print made. The T-shirt is flash-dried.
3. The yellow screen is lowered, yellow ink applied, and a print made.
4. This process is repeated 49 more times, ensuring consistent ink application, squeegee pressure, and accurate registration for each T-shirt.
5. Periodically, the screens may need light cleaning of any dried ink along the edges during the print run to maintain print quality.
6. At the end of the 50 T-shirts, both screens are thoroughly cleaned with screen wash and water, dried, and stored for future use or reclaiming. --- a smooth first pass.
Squeegee Pass: Hold the squeegee at a consistent angle (typically 45-75 degrees) with firm, even pressure. Pull the squeegee in a single, smooth stroke across the design area, pushing the ink through the open mesh onto the substrate. The pressure and angle are critical for even ink deposition.
Screen Lifting: Carefully lift the screen, ensuring the design has transferred completely.
Substrate Removal: Remove the printed substrate.
Drying: Place the printed item in a drying rack or tunnel dryer. Textile prints often require heat curing (e.g., with a heat press or flash dryer) to achieve permanence and wash fastness. 2.
2. Reproduction of the Design Using the Same Screen Once the initial print is successfully made, the same prepared screen can be used to reproduce the design multiple times. This is the core advantage of screen printing for batch production.
1. Cleaning the Screen (Between Prints/Runs): Ink Removal: After a print run, or if there's a pause in printing, flood the screen with ink to prevent it from drying in the mesh.
Wipe Down: Use a squeegee to scrape excess ink back into the container.
Washing: Use appropriate screen wash solvent (for plastisol/solvent inks) or water (for water-based inks) to clean both sides of the screen thoroughly. Remove all ink residues from the mesh and stencil. This step is critical to prevent clogging and ensure the screen is ready for the next print.
Drying: Allow the screen to dry completely before the next use, especially if changing ink types or storing it.
2. Maintaining Registration: For subsequent prints, ensure the substrate is placed in the exact same position using the established registration guides. This is crucial for consistent image placement. For multi-colour jobs, the registration marks on the artwork itself (if available) and the platen guides must be meticulously aligned for each colour pass.
3. Continuous Printing Cycle: Repeat the Printing Process: Once the first print is removed and the screen (if necessary) briefly cleaned, a new substrate is placed on the printing surface.
Apply Ink and Squeegee: The screen is lowered, ink is applied (or re-flooded), and a squeegee pass is made.
Remove and Dry: The new print is removed and sent for drying/curing. This cycle is repeated until the desired number of reproductions is achieved.
Example Scenario (Nigerian Context): A local youth group needs 50 T-shirts printed with their club logo for an upcoming event. The logo is a simple two-colour design.
Initial Print Production:
1. Screen Prep: Two screens are prepared – one for each colour – using the photo emulsion method for durability.
2. Ink Prep: Two colours of plastisol ink are mixed (e.g., green and yellow, matching the club's colours).
3. Setup: A T-shirt platen is set up. Registration guides are marked for the T-shirt placement.
4. First Colour (Green): The T-shirt is placed, the first screen (green logo part) is lowered, green ink is flooded, and a squeegee pass is made. The T-shirt is flash-dried (partially cured) to prevent smudging.
5. Second Colour (Yellow): While still on the platen, the first screen is lifted, and the second screen (yellow text part) is carefully lowered, aligning its registration marks with the partially printed green design. Yellow ink is flooded, and a squeegee pass is made.
6. Full Cure: The two-colour printed T-shirt is removed and sent through a tunnel dryer for full curing.
Reproduction:
1. After the first T-shirt is completed, a new blank T-shirt is placed on the platen, aligning it with the same registration guides.
2. The green screen is lowered, green ink applied, and a print made. The T-shirt is flash-dried.
3. The yellow screen is lowered, yellow ink applied, and a print made.
4. This process is repeated 49 more times, ensuring consistent ink application, squeegee pressure, and accurate registration for each T-shirt.
5. Periodically, the screens may need light cleaning of any dried ink along the edges during the print run to maintain print quality.
6. At the end of the 50 T-shirts, both screens are thoroughly cleaned with screen wash and water, dried, Teacher Activities: Introduction (10 minutes): Recall previous knowledge on stencil making and screen preparation. Briefly explain the objectives for the lesson, focusing on the practical "how-to" of making prints and reproductions. Display various examples of screen-printed items (T-shirts, bags, posters) to motivate students and connect to real-life applications. Demonstration of Initial Print Production (30 minutes): Set up a screen printing station (prepared screen, ink, squeegee, substrate – e.g., paper or fabric swatch).
Step-by-step demonstration: Show how to position the substrate accurately using guides. Demonstrate proper screen lowering technique. Show how to apply a bead of ink and flood the screen. Execute a clean, firm, consistent squeegee pass, emphasizing angle and pressure. Carefully lift the screen to reveal the print. Explain the importance of off-contact distance and how to achieve it. Discuss common issues (e.g., uneven print, blur, ink bleeding) and troubleshooting. Demonstration of Reproduction Technique (20 minutes): Using the same prepared screen, demonstrate how to make a second and third print. Emphasize maintaining consistency in substrate placement and squeegee technique. Briefly demonstrate how to clean the screen minimally between prints (e.g., wiping off excess ink) and thoroughly after a print run. Discuss how to manage a batch production efficiently.
Supervision and Guidance: Circulate among student groups, providing individual feedback and correcting techniques during practical sessions. Answer questions and address specific challenges. Ensure safety protocols are followed (e.g., proper ventilation, handling of inks and solvents, use of gloves).
Student Activities: Observation and Note-Taking (20 minutes): Students observe the teacher's demonstrations keenly, taking detailed notes on each step of print production and reproduction. They ask clarifying questions during the demonstration. Group Practical Session – Initial Print (40 minutes): Students divide into small groups (e.g., 3-4 per group). Each group is provided with a prepared screen (with a simple design), ink, squeegee, and several pieces of practice substrate (e.g., old T-shirts, paper, cardboard). Under teacher supervision, groups practice making their first successful print from the screen, following the demonstrated steps. They experiment with squeegee pressure and angle. Group Practical Session – Reproduction (40 minutes): Using the same screen and their initial successful print, students proceed to make multiple reproductions of the design on different substrates. They focus on achieving consistent quality across all prints. Students practice quick placement of substrates and efficient squeegee passes for a batch run. They discuss within their groups how to troubleshoot minor issues they encounter.
Clean-up (10 minutes): Students participate in cleaning the screens, squeegees, and work area, following the teacher's instructions for proper disposal of waste and ink. ---
Entrepreneurship in Fashion and Events: Many young entrepreneurs in Nigeria leverage screen printing to create customized T-shirts, hoodies, and face caps for fashion brands, event merchandise (e.g., concerts, festivals, conferences), and political campaigns. Students with these skills can start their own printing businesses with relatively low capital, catering to the high demand for personalized apparel in the local market. This can be integrated by inviting a local small-scale screen printing entrepreneur to share their experience.
Community Development and Awareness: Screen printing is an effective and affordable method for producing posters, banners, and flyers for public health campaigns (e.g., malaria prevention, hygiene), community announcements, and educational materials in local languages. Students can apply their skills by designing and printing awareness materials for school events or local community initiatives, collaborating with NGOs or local government bodies. For example, printing posters for a local 'clean up Nigeria' campaign.
Local Craft and Souvenir Production: Nigerian artists and craftspeople use screen printing to add designs to fabrics, bags, and other items, enhancing their aesthetic appeal and market value. This technique can be applied to create unique souvenirs, branded shopping bags for local markets, or patterned fabrics for traditional attire. Students could develop a small project where they design and print a traditional pattern onto a fabric to be used as part of a local craft item (e.g., a small bag, cushion cover). ---