Handmade Papers: Innovation, Technology, and Design

ABSTRACT A mini-review is presented on handmade papers regarding their origin from papyrus to modern paper mill start-ups in the USA. The overview succinctly covers the process of making handmade papers, value addition, and product design. The scientific investigations on obtaining HMP from innovative raw materials such as coffee beans, agro-waste, seaweeds, hyacinth flowers, and others are detailed. The role of handmade paper in conservation along with the environmental and economic benefits of recycled handmade paper are contained within. The mini-review concludes with a promising future for handmade papers that would encourage sustainability.

compost made of 50% water hyacinth and 50% kitchen bio-waste solid was the best quality (Islam et al. 2021).
The HMP paper is a semi-manual cottage industry product. The method of HMP making could be purified further by minimizing water, energy, and fossil-based additives demand. For example, this could be achieved by installing a water recycling plant implemented by Auroville papers, in India (Herve 2022). Also, consumer awareness by preferring raw unbleached paper to bleached paper would impel sustainability. The HMP as conservation material is designed skillfully for preservation, repair, and bookbinding. These HMPs are structured to specific purity and strength that is unique and differs from the readily available acid-free paper for printing graphics. Some of the finest European and Oriental HMPs are employed with the intent of preservation and conservation (CXD International 2022). On the other hand, the conservation framer ensures that the work of art created with HMP remains stable and is preserved over an extended period. The goal is to protect it from environmental stimuli (Seery 2013). Paper Chemistry is at the heart of handmade paper conservation and requires it to be cultivated among the chemists of future generations (Hand Papermaking, Inc 2008). Hence, the HMP can be utilized as a conservation material and HMP artworks are required to be preserved. Also, the process of handmade paper-making ought to be simplified, and purified.

Innovation and technology
The handmade paper could be generated by recycling any paper, it could be made from tree-free (nonwood) raw materials as cited further in an eco-friendly manner. The elephant dung, corn husk, hemp, and linen fibers are successfully utilized to make HMP (Bluecat Paper 2020a). In the same vine, Areca nuts and cardboard paper were de-lignified by cooking in 5%, 10%, and 15% H 2 O 2 at 80°C for 90,120, and 150 minutes. The optimum conditions were concluded to be belching with 15% H 2 O 2 for 150 minutes (Dewi et al. 2020). The brightness level of the areca nut paper was directly proportional to the bleaching time acquiring a probability value of 0.0018. Likewise, the bleaching time was inversely proportional to the tensile strength in kN/m 2 , gaining the probability value of 0.0297. The brightness  level and tensile strengths were 14.71% and 69.50 kN/m 2, respectively, for a paper with a grammage of 282 gm/cm 2 , a thickness of 0.88 mm, and a water content of 6.5% (Dewi et al. 2020). The pulp of waste banana fibers was utilized for making handmade paper of 60 g/m 2 . Its drainage resistance was 71 °SR, the tensile index was 23.7 N.m/g, the burst index was 2.2 kPa.m 2 /g, and the tear index was 5.0 mN.m 2 / g. The kappa number was 29.9, with a pulp yield of 29.3% acquired on processing waste banana fibers with 12% NaOH for 150 minutes (Arafat et al. 2018). Stems of aquatic plants, namely Cyperus digitatus, Cyperus halpan, Cyperus rotundas, Scirpus grosses, and Typha angustifolia were studied for handmade paper making on varied parameters with the other non-wood and aquatic plants from Musa paradisiaca, Bambusa tulda, Saccharum sp., Arundo donax, and others. The results are summarized in Table 1. Due to the Cellulose content of Cyperus rotundus (42.58 ± 1.32%), Scirpus grossus (36.21 ± 2.81%), and Typha angustifolia (44.05 ± 0.49%) >34%, these seaweed plants were inferred as appropriate for pulp and papermaking units (Bidin et al. 2015).
Interestingly, the HMP was constituted from the waste office papers and PPE kits in ten varied proportions and evaluated for hardness, moisture content, and photometry analysis. As hypothesized, increased PPE content was inversely proportional to the moisture content and directly proportional to the hardness gained of HMP and accordingly would be the end-user. The HMP with 50% PPE waste and 50% office paper exhibited high photometric values (Kumar et al. 2021). Aguilar-Rivera and team suggest HMP from the cellulosic coffee pulp as displayed in Figure 2a, denoting 25% coffee pulp with 75% other waste fibers and papers and 2b indicating 50% coffee pulp paper with 50% other waste fibers and papers (Aguilar-Rivera et al. 2014). Agro-residues such as wheat and rice straw were investigated and concluded to be the cost-effective non-wood raw material for making HMP. The maximum fiber length was reported to be 3.84 mm and 2.7 mm for wheat and rice straw correspondingly (Chauhan, Agarwal, and Khan 2015). Likewise, agricultural waste from banana fibers and sugarcane bagasse was experimented with for making HMP. It was noted that the bagasse paper with 2% calcium carbonate and 2% starch added to it gained the highest values for GSM of 108, pH of 7.29, and thickness of 0.25. Whereas its equivalent banana fibers obtained the highest amounts of the bulk of 640 and moisture content of 66.67. The agro-waste served as a fruitful raw material for manufacturing HMP (Khalsa and Dwivedi 2017). Additionally, Sottile et al., extracted cellulose materials from the fresh Opuntia ficus indica cladodes (prickly pears) and obtained a slurry with hot water treatment for making HMP (Sottile et al. 2021).
Traditional, Hanji, Korean handmade paper, 309 in number was studied and observed to demonstrate color value ranges of L* (69.9-95.9), a* [(− 3)-3], and b* (0-20). The pH was noted to be from 5.3 to 9.8. Much of the Hanji HMP had a grammage in the range of 100-150 g/m 2 and a thickness inbetween 100-150 µm. The HMP sheets were formed by two techniques: Heullimtteugi (criss-cross fiber orientation) and Gadumtteugi (on-grain fiber alignment). The tensile strength of on-grain fibers paper was in the range of 352.8-3000 N/min, which was higher than 183.1-2000 N/m for criss-cross fibers paper. The folding endurance of 60% of the Hanji papers was in-between 1.2 and 500 times. The Korean handmade papers called Hanji paper are made of fibers from the barks of mulberry, gampi, and mutsumata. The Gas Chromatography-Mass Spectroscopy analysis identified cellulose as the primary content in Hanji paper besides lignin monomers and terpenic compounds (Han et al. 2021). The traditional Chinese paper Xuan was studied for photo yellowing of the paper with UVA photolysis. A significant yellowing of paper occurred when irradiated in the dry state compared to the wet state. The HMP demonstrated auto-fluorescence in the blue spectral range (450-500 nm). As illustrated in Figure 3, the morphological study on SEM indicated that the Xuan HMP is made with rice straw fibers and blue sandalwood fibers (Tang and Smith 2013).
Overall, the research development on HMP is focused on identifying and utilizing alternative sources of natural fibers such as coffee pulp, seaweed, and areca nut plants for making HMP. Generating the best out-of-waste office papers and cardboard cartoons for developing HMP. The need for significant research and development in HMP is identified to achieve greater benefits. Innovation in HMP needs a breakthrough in varied aspects such as novel raw material sourcing,  refined processing, and diversified product development Additionally, it calls for exclusive packaging, branding, and marketing strategies to be developed for promulgating HMP.

Product design and value generation
Product development and value addition are significant aspects of designing HMP. For example, a few of the HMP product innovations by Auroville papers are displayed in Figure 4, demonstrating the development from cotton rags to HMP flowers, jewelry, and stationery.
The Daqian handmade paper with a grammage of 25.46 g/m 2 and thickness of 94 μm was valueadded through coloration with plant-based materials from the gardenia, pagoda bud, turmeric, and Amur cork tree. All the materials yielded yellow-colored handmade paper; the maximum b* a value of 57.5 was obtained with a Gardenia extract solution of pH 4.51. The tensile strength values and folding endurance of the dyed papers were enhanced via post-coloration, as depicted in Figure 5. The pH of the colored handmade papers was in the acidic range of 6.02 to 6.98 (Luo and Xiujuan 2021).
In the same vein, Saakshy et al. reviewed handmade paper. They suggested that the HMP made in India should utilize natural colors from Terminalia arjuna, Terminalia chebula, Quercus infectoria Acacia catechu, and others due to the life-threatening carcinogenicity of azo group-containing and benzidine-based dyes. This is essential to prevent the decline in export demand for HMP to the countries such as Germany, the UK, and the USA due to legal rules (Azo-ban) applied by the respective countries (Saakshy, Sharma and Jain 2013). Additionally, a project on HMP conducted by Menon et al. concluded that HMP could play a vital role in women's empowerment and promulgating handmade eco-friendly products from HMP; for example, paper bags would enable curtailing our dependency on plastic bags. Establishing HMP units would encourage entrepreneurship and skilled craftsmanship, especially in rural India. In this way, it would contribute toward value generation and self-sustainability (Menon et al. 2020).
Interestingly an ancient "Echizen Washi" Japanese HMP was studied regarding ergonomics in relevance to skilled craftsmanship and handling large-formatted Japanese HMP. A pair of mother and daughter were selected for the study, as depicted in Figure 6. The following steps were involved.
The method called Sukisu in combination with the Skigeta collective known as Sugeta was sequentially performed. It was noted that the craftsmanship improved with work experience in making waste-free   (Kawamori et al. 2020). and quality Echizen Washi HMP (Kawamori et al. 2020), thereby affecting productivity and profitability.
The concepts for merging HMP with plant-based colors such as turmeric, manjistha, others and value-added materials, namely leaf imprints, and jute rouching techniques, would further propel the sustainability aspect of HMP. HMP is beautiful and luxurious. The artists, designers, and consumer awareness could benefit the cottage industry to survive and prosper economically. Thus, globally the HMP production and market are at a niche level. To propel its market new sustainable products need to be designed and developed.

Eco-friendly handmade paper
Handmade paper making is a manual process in contrast to the industrial handling of mill-made paper. The HMP making is elaborate, obtaining one paper at a time with natural variations and unique traits. The machine-made paper yield is the large, continuous, and consistent quality of paper acquired (Bluecat Paper 2018b). The worldwide production of paper was 407 million metric tons in 2015 and was predicted to reach 500 million metric tons by 2020 (Bajpai 2018). More than 15 million Christmas trees are uprooted for manufacturing papers for gift wrapping. One kilogram of paper generated three and a half kilograms of carbon dioxide. It consumes one and a half kilograms of coal as fuel during production (Our Endangered World 2021). Tree-free handmade papers offer a sustainable answer to resolve the environmental crisis arising due to mill-made paper (Mathew 2020). The tree-free papers could be constituted from the bagasse. Bagasse is a sugarcane waste collected after juice extraction. It is high in cellulose which is 45% and therefore suitable for making HMPs and others. Similarly, the HMPs could be developed from bamboo and kenaf plants (Mathew 2020). Alternatively, calcium carbonate bonded with a small amount of high-density polyethylene resin generated limestone paper. Limestone paper is not biodegradable however it is photo-degradable, compostable, and recyclable (Mathew 2020). The handmade paper is 100% recycled non-wood paper. HMP production consumes 50% less energy and 75% less water than machine-made paper. It generated 90% fewer water effluents and 70% fewer air emissions (Bluecat Paper 2018a).
In summary, HMP making is a skilled art promulgating HMP promotes the survival of both the art and artists. The regional local people involved in making HMP are supported hence, sustainable (Goswami 2021). The paper could be recycled up to six times. Recycling one ton of paper protects 17 trees, 7,000 gallons of water, and 380 gallons of oil (West 2020). It conserves 3.3 cubic yards of landfill space and 4,000 kilowatts of energy. These savings could provide six months of power supply to the average U.S. home. Additionally, it prevents greenhouse gas emissions by one metric ton of carbon equivalent (West 2020).

Miscellaneous
The handmade paper and wheat straw waste sludge were utilized as a substrate to cultivate the Pleurotus citrinopileatus variety of golden oyster mushrooms. The mushrooms gained had biological efficiency of 88.9%. The moisture, protein, fat, ash, and carbohydrate content were 93.73%, 14.48 g/100 g, 0.17 g/100 g, 0.29 g/100 g, and 2.60 g/100 g, respectively. The carpophores cultivated on the handmade paper and wheat straw exhibited no base pair mutations and safe levels of frameshift mutagens hence suitable for consumption. Conclusively, it would enable fruitful utilization of waste sludge and thereby protect the environment (Kulshreshthaa et al. 2013). Waste from the juice center of the apple, pineapple, banana, and orange was utilized to isolate fungi by the Sabouraud dextrose agar (SDA) method in which the plates were incubated for 7 days at 28 ± 2EC. The five fungal isolates, namely, Alternaria sp., A. niger, Cladosporium sp. and Penicillium sp. under acidic conditions and Alternaria sp., A. niger, Helminthosporium sp., Penicillium sp., under alkaline conditions were identified to be potent for handmade paper industry for cellulase production by submerged fermentation. The czapk dox broth at 28 ± 2EC, pH of 5.0 with 2 days of incubation in the submerged fermentation process was concluded to be ideal (Singh, Sharma, and Gupta 2018). Innovative end uses and out-of-the-box applications of HMP could be studied before long. Similarly, the Seed paper is the HMPs that could be made from cotton rags, elephant poo, flax, mulberry, and others (Bluecat Paper 2020b). The seeds of flowers such as marigold, begonia, and vegetables such as tomatoes, carrots, and basil are embedded in the seed paper. The fruits and vegetables cultivate further by implanting the seed paper in fertile soil. The paper decomposes naturally hence, sustainable (Bluecat Paper 2020b).

Conclusion
To summarize, traditional paper-making faced a decline in mass production and profitability. However, with investigations with varied alternative natural materials for pulp making, product designing, and sustainability at the forefront, the handmade paper-making market has gained great momentum and a prospective future. Interestingly the Jinjiang HMP makers suggest associating traditional handmade paper making with travel and tourism as a symbol of cultural heritage to maintain its vitality (CGTN 2022). Overall, the following conclusions could be made from the review.
• The study cited several novel sources of raw materials for obtaining handmade paper such as sugarcane bagasse, wheat, and rice straw, prickly pear, and others. • The significant technical information regarding the HMP grammage, thickness, tensile strength, moisture content, pH, and others influencing the quality of HMP obtained were studied. • The novel and beautiful product development with HMP was covered.
• The economic and environmental benefits of HMP were summarized in the review paper.
On critical analysis, it was realized that there needs to be a significant breakthrough in the research and development of HMP. Parallelly, there are gaps noted in the form of insufficient product development and marketing strategies to connect HMP globally. Nonetheless, it is imperative to purify the handmade papermaking process for enhanced sustainable outcomes.

Highlights
• The paper covers the scientific and technical aspects of HMP making, and the essential properties of HMP are discussed. • The overview supports that Handmade paper encompasses the immense potential to propel sustainability. • The world of HMP is unique; extraordinary, beautiful, and functional products are created with HMP as explained by images. • Finally, the mini-review concludes a potentially bright future for HMP that requires to be focussed and strengthened.

Future work
The mini-review summarizes handmade paper making and products from past to present. The study suggests promulgating and investigating the value generation and sustainability aspect of the HMP. This could be achieved by investing in HMP cottage industries and performing a life cycle analysis of the HMP. The surplus natural raw materials, fibers, and papers combined with plant-based colors and subsequent eco-friendly finishing and packaging would propel sustainable HMP, therefore recommended for future research and development. An ecological, creative, and self-sufficient HMP cottage industry is envisioned for the future.

Disclosure statement
No potential conflict of interest was reported by the authors.